The billion dollar club of India - Market capitalisation of Indian companies

Biggest companies in India by Market Capitalization

The biggest losers in market capitalization were again Reliance, ONGC and Bharti Airtel. Cipla slipped in rank by 8.

-		Name of Company	Market Cap	Market Cap	Change	Change
-		As on market closing on April 27, 2007 (Friday)	INR	Billion Dollars	in	in MktCap
-		(Changes from 26th April 2007 - Thursday closing)	(In Crores)	$1 = INR 41	Rank	INR Crores
1		Reliance Industries Ltd	214,349.41	52.28	0	-8,158.99
2		Oil & Natural Gas Corporation Ltd	198,765.42	48.48	0	-6,641.20
3		Bharti Airtel Ltd	156,651.56	38.21	0	-6,787.44
4		National Thermal Power Corporation Ltd	130,814.29	31.91	0	329.82
5		Tata Consultancy Services Ltd	120,804.57	29.46	0	-494.20
6		Infosys Technologies Ltd	111,949.03	27.30	0	-605.27
7		Reliance Communications Ltd	94,082.96	22.95	0	-2,739.78
8		ICICI Bank Ltd	83,468.58	20.36	0	-2,717.77
9		Wipro Ltd	81,500.01	19.88	0	424.74
10		Bharat Heavy Electricals Ltd	60,907.30	14.86	0	-548.26
11		ITC Ltd	60,425.87	14.74	0	-263.21
12		State Bank of India	57,829.72	14.10	0	-2,486.76
13		Steel Authority of India Ltd	54,645.20	13.33	0	-722.82
14		Indian Oil Corporation Ltd	50,896.13	12.41	0	969.45
15		Larsen & Toubro Ltd	47,651.81	11.62	0	-718.09
16		Hindustan Lever Ltd	46,233.13	11.28	0	-1,147.55
17		Housing Development Finance Corporation Ltd	42,660.71	10.41	0	-1,258.71
18		Reliance Petroleum Ltd	36,450.00	8.89	0	-495.00
19		Unitech Ltd	34,362.79	8.38	0	-1,806.00
20		Suzlon Energy Ltd	34,095.81	8.32	0	-1,151.06
21		HDFC Bank Ltd	32,465.95	7.92	0	-448.74
22		Tata Steel Ltd	31,209.12	7.61	0	-1,323.48
23		Satyam Computer Services Ltd	30,702.61	7.49	0	459.96
24		Tata Motors Ltd	28,845.24	7.04	0	-709.09
25		Sterlite Industries India Ltd	28,351.97	6.92	0	-1,167.25
26		Hindustan Zinc Ltd	27,532.18	6.72	0	-676.05
27		National Mineral Development Corporation Ltd	26,365.36	6.43	0	66.08
28		Bajaj Auto Ltd	24,855.22	6.06	0	-352.62
29		Gail India Ltd	24,063.02	5.87	0	-477.79
30		Maruti Udyog Ltd	22,968.35	5.60	0	-53.45
31		Grasim Industries Ltd	22,197.40	5.41	0	-706.35
32		i-flex Solutions Ltd	20,662.65	5.04	0	13.33
33		Siemens Ltd	19,724.71	4.81	2	300.92
34		Sun Pharmaceutical Industries Ltd	19,688.01	4.80	-1	-660.45
35		Mahindra & Mahindra Ltd	18,720.60	4.57	1	-60.12
36		Gujarat Ambuja Cements Ltd	17,822.74	4.35	1	-250.28
37		ABB Ltd	17,549.19	4.28	3	196.44
38		Reliance Capital Ltd	17,416.59	4.25	0	-550.22
39		Hindalco Industries Ltd	17,139.79	4.18	2	-69.56
40		Tech Mahindra Ltd	17,082.44	4.17	-1	-350.51
41		Kotak Mahindra Bank Ltd	17,000.87	4.15	1	531.63
42		Cipla Ltd	16,875.00	4.12	-8	-2,809.91
43		Punjab National Bank	15,735.17	3.84	0	-354.72
44		National Aluminium Company Ltd	15,676.05	3.82	0	-347.93
45		ACC Ltd	15,399.93	3.76	0	-163.95
46		Power Finance Corporation Ltd	14,197.87	3.46	0	-321.37
47		Ranbaxy Laboratories Ltd	13,787.55	3.36	0	-81.99
48		Bharat Electronics Ltd	13,526.40	3.30	3	244.40
49		Hero Honda Motors Ltd	13,343.12	3.25	0	-237.63
50		Jaiprakash Associates Ltd	13,329.77	3.25	-2	-259.80
51		Container Corporation of India Ltd	13,101.62	3.20	1	-90.99
52		GMR Infrastructure Ltd	13,049.68	3.18	-2	-470.14
53		UTI Bank Ltd	12,829.69	3.13	0	-274.59
54		Zee Entertainment Enterprises Ltd	12,450.43	3.04	0	-166.87
55		Videsh Sanchar Nigam Ltd	12,418.88	3.03	0	-146.78
56		Motor Industries Company Ltd	12,255.36	2.99	6	1,278.37
57		Bharat Petroleum Corporation Ltd	12,232.78	2.98	-1	-48.81
58		Dr Reddys Laboratories Ltd	11,951.99	2.92	-1	-88.15
59		Tata Power Company Ltd	11,559.21	2.82	-1	-191.96
60		Infrastructure Development Finance Company Ltd	10,949.65	2.67	0	-185.78
61		Sun TV Ltd	10,923.75	2.66	-2	-234.91
62		Reliance Energy Ltd	10,846.20	2.65	-1	-180.10
63		HCL Technologies Ltd	10,583.46	2.58	0	12.99
64		Neyveli Lignite Corporation Ltd	10,376.63	2.53	0	-184.55
65		Ultratech Cement Ltd	9,999.33	2.44	1	-60.38
66		GlaxoSmithKline Pharmaceuticals Ltd	9,842.07	2.40	-1	-327.38
67		Aban Offshore Ltd	9,571.07	2.33	8	380.53
68		Aditya Birla Nuvo Ltd	9,570.44	2.33	-1	-199.99
69		Nestle India Ltd	9,566.85	2.33	4	91.11
70		Bank of India	9,526.27	2.32	-2	-207.15
71		Mahanagar Telephone Nigam Ltd	9,490.95	2.31	-1	-154.35
72		JSW Steel Ltd	9,414.02	2.30	-3	-235.31
73		Videocon Industries Ltd	9,338.86	2.28	-2	-216.57
74		Indian Petrochemicals Corporation Ltd	9,228.57	2.25	-2	-267.63
75		Hindustan Petroleum Corporation Ltd	9,119.49	2.22	-1	-161.18
76		Canara Bank	9,071.25	2.21	0	-114.80
77		Bank of Baroda	8,848.02	2.16	0	-103.82
78		Jindal Steel & Power Ltd	8,514.22	2.08	1	-33.87
79		Indian Hotels Company Ltd	8,438.69	2.06	1	-79.20
80		Financial Technologies India Ltd	8,412.85	2.05	-2	-300.05
81		Dabur India Ltd	8,193.08	2.00	0	-267.49
82		Indiabulls Financial Services Ltd	8,091.36	1.97	0	-201.57
83		Crompton Greaves Ltd	7,954.50	1.94	2	256.60
84		United Spirits Ltd	7,907.67	1.93	-1	-169.12
85		Glenmark Pharmaceuticals Ltd	7,659.11	1.87	-1	-363.18
86		Asian Paints Ltd	7,558.00	1.84	0	-117.98
87		Hindustan Copper Ltd	7,136.75	1.74	0	-303.45
88		Bharat Forge Ltd	7,072.55	1.73	0	-151.40
89		Mangalore Refinery & Petrochemicals Ltd	6,967.79	1.70	2	113.94
90		Sesa Goa Ltd	6,940.90	1.69	0	-16.34
91		BF Utilities Ltd	6,895.62	1.68	-2	-152.18
92		Indian Overseas Bank	6,379.61	1.56	0	-98.06
93		Sobha Developers Ltd	6,317.66	1.54	0	-153.82
94		United Phosphorus Ltd	6,314.81	1.54	0	-42.19
95		Patni Computer Systems Ltd	6,298.74	1.54	6	367.83
96		Essar Oil Ltd	6,244.63	1.52	-1	-62.67
97		Centurion Bank of Punjab Ltd	6,220.42	1.52	1	180.19
98		Jet Airways India Ltd	6,136.62	1.50	-1	-110.94
99		Parsvnath Developers Ltd	6,118.06	1.49	0	110.82
100		Industrial Development Bank of India Ltd	6,106.30	1.49	-4	-191.95
101		Shipping Corporation of India Ltd	5,816.84	1.42	2	93.16
102		United Breweries Ltd	5,806.17	1.42	0	-81.02
103		Pantaloon Retail India Ltd	5,785.83	1.41	-3	-153.35
104		Cummins India Ltd	5,622.21	1.37	0	-88.11
105		Lupin Ltd	5,593.21	1.36	0	-102.82
106		Union Bank of India	5,440.12	1.33	2	-83.34
107		Century Textiles & Industries Ltd	5,434.33	1.33	-1	-218.66
108		Adani Enterprises Ltd	5,421.48	1.32	-1	-171.31
109		Oriental Bank of Commerce	5,342.76	1.30	0	-50.11
110		Nicholas Piramal India Ltd	5,245.18	1.28	0	20.90
111		Ashok Leyland Ltd	5,110.14	1.25	0	-86.05
112		Mphasis Ltd	5,025.52	1.23	0	-56.60
113		Thermax Ltd	4,950.94	1.21	0	-29.79
114		Tata Teleservices Maharashtra Ltd	4,876.59	1.19	0	0.00
115		Biocon Ltd	4,758.50	1.16	0	-88.00
116		Areva T&D India Ltd	4,702.93	1.15	1	-13.36
117		Amtek Auto Ltd	4,668.83	1.14	1	-33.65
118		Tata Chemicals Ltd	4,637.61	1.13	1	-60.23
119		Colgate Palmolive India Ltd	4,632.60	1.13	4	0.68
120		Godrej Industries Ltd	4,617.09	1.13	-4	-150.30
121		Divis Laboratories Ltd	4,605.18	1.12	0	-61.65
122		Wockhardt Ltd	4,588.10	1.12	-2	-108.34
123		Tata Tea Ltd	4,550.32	1.11	-1	-116.29
124		Corporation Bank	4,531.99	1.11	0	-82.48
125		Essar Steel Ltd	4,507.95	1.10	0	-85.49
126		Deccan Chronicle Holdings Ltd	4,421.98	1.08	5	261.73
127		Titan Industries Ltd	4,281.79	1.04	0	9.10
128		Yes Bank Ltd	4,247.60	1.04	-2	-113.40
129		Anant Raj Industries Ltd	4,214.28	1.03	1	34.28
130		IVRCL Infrastructures & Projects Ltd	4,079.83	1.00	-2	-110.21
131		HT Media Ltd	4,063.88	0.99	-2	-118.29
132		Cadila Healthcare Ltd	4,012.73	0.98	0	-89.19
133		Praj Industries Ltd	4,008.19	0.98	2	-40.22

The billion dollar club of India - Market capitalisation of Indian companies

Biggest companies in India by Market Capitalization

The biggest gainer in market capitalization was ONGC which added more than 5176 Crores. Reliance Industries also gained 2703 Crores. The biggest loser was Infosys, having lost more than 2245 Crores.
As of today, the total market capitalisation of BSE is INR 3,731,496 Crores. In billion $, the market cap of BSE companies is $888.45 Bn, up by $8 Bn.
Market capitalization of SENSEX (BSE 30 Index) = 1,856,917 Crores ($442.12 Bn)

-		Name of Company	Market Cap	Market Cap	Change	Change
-		As on market closing on April 25, 2007 (Wednesday)	INR	Billion Dollars	in	in MktCap
-		(Changes from 24rd April 2007 - Tuesday closing)	(In Crores)	$1 = INR 42	Rank	INR Crores
1		Reliance Industries Ltd	222,940.38	53.08	0	2,703.41
2		Oil & Natural Gas Corporation Ltd	208,069.52	49.54	0	5,176.07
3		Bharti Airtel Ltd	163,581.20	38.95	0	-2,066.57
4		National Thermal Power Corporation Ltd	129,288.88	30.78	0	-1,278.05
5		Tata Consultancy Services Ltd	119,468.77	28.44	0	-489.31
6		Infosys Technologies Ltd	112,568.24	26.80	0	-2,245.34
7		Reliance Communications Ltd	97,160.10	23.13	0	81.78
8		ICICI Bank Ltd	86,007.55	20.48	0	1,054.92
9		Wipro Ltd	80,053.01	19.06	0	237.57
10		Bharat Heavy Electricals Ltd	61,028.46	14.53	0	-12.24
11		ITC Ltd	60,820.68	14.48	1	1,992.89
12		State Bank of India	59,950.71	14.27	-1	326.31
13		Steel Authority of India Ltd	55,388.67	13.19	0	20.65
14		Indian Oil Corporation Ltd	48,268.10	11.49	1	426.32
15		Larsen & Toubro Ltd	47,828.85	11.39	-1	-417.82
16		Hindustan Lever Ltd	46,608.29	11.10	0	893.77
17		Housing Development Finance Corporation Ltd	44,328.02	10.55	0	1,058.83
18		Unitech Ltd	36,355.48	8.66	1	1,018.67
19		Reliance Petroleum Ltd	36,315.00	8.65	-1	675.00
20		Suzlon Energy Ltd	34,241.13	8.15	0	569.77
21		Tata Steel Ltd	33,133.39	7.89	0	-481.79
22		HDFC Bank Ltd	32,943.44	7.84	0	570.11
23		Satyam Computer Services Ltd	30,650.04	7.30	0	-558.53
24		Sterlite Industries India Ltd	29,561.11	7.04	0	-156.38
25		Tata Motors Ltd	29,242.17	6.96	1	612.74
26		Hindustan Zinc Ltd	27,665.28	6.59	-1	-1,075.34
27		National Mineral Development Corporation Ltd	26,431.44	6.29	0	0.00
28		Bajaj Auto Ltd	24,657.41	5.87	0	-75.38
29		Gail India Ltd	23,969.99	5.71	0	-452.42
30		Maruti Udyog Ltd	22,797.89	5.43	0	-153.12
31		Grasim Industries Ltd	22,383.96	5.33	0	562.88
32		Sun Pharmaceutical Industries Ltd	20,181.21	4.81	0	-10.45
33		i-flex Solutions Ltd	19,977.18	4.76	0	22.90
34		Cipla Ltd	19,607.17	4.67	1	1,006.59
35		Siemens Ltd	18,852.31	4.49	-1	-51.42
36		Mahindra & Mahindra Ltd	18,714.47	4.46	0	466.21
37		Gujarat Ambuja Cements Ltd	18,285.37	4.35	1	182.02
38		Reliance Capital Ltd	18,230.87	4.34	-1	110.53
39		Tech Mahindra Ltd	17,387.76	4.14	0	-209.73
40		Hindalco Industries Ltd	17,331.07	4.13	0	104.33
41		ABB Ltd	17,117.96	4.08	0	312.14
42		Kotak Mahindra Bank Ltd	16,417.05	3.91	0	96.22
43		National Aluminium Company Ltd	16,168.95	3.85	1	306.05
44		Punjab National Bank	16,007.91	3.81	-1	61.48
45		ACC Ltd	15,602.29	3.71	0	292.30
46		Power Finance Corporation Ltd	14,691.41	3.50	0	510.76
47		GMR Infrastructure Ltd	13,801.24	3.29	0	223.48
48		Ranbaxy Laboratories Ltd	13,755.88	3.28	5	743.51
49		Hero Honda Motors Ltd	13,725.52	3.27	1	525.18
50		Jaiprakash Associates Ltd	13,636.71	3.25	-2	320.09
51		Container Corporation of India Ltd	13,268.32	3.16	-2	-16.25
52		Bharat Electronics Ltd	13,257.60	3.16	-1	72.80
53		UTI Bank Ltd	13,154.97	3.13	-1	-29.57
54		Videsh Sanchar Nigam Ltd	12,616.95	3.00	1	7.13
55		Zee Entertainment Enterprises Ltd	12,465.61	2.97	-1	-338.08
56		Dr Reddys Laboratories Ltd	11,941.07	2.84	0	-46.18
57		Bharat Petroleum Corporation Ltd	11,874.85	2.83	0	189.81
58		Tata Power Company Ltd	11,845.18	2.82	1	324.55
59		Infrastructure Development Finance Company Ltd	11,681.50	2.78	-1	152.00
60		Sun TV Ltd	11,295.07	2.69	0	49.26
61		Reliance Energy Ltd	11,158.44	2.66	0	-34.10
62		MMTC Ltd	10,900.00	2.60	0	-225.00
63		HCL Technologies Ltd	10,792.92	2.57	0	-90.93
64		Motor Industries Company Ltd	10,769.77	2.56	0	64.42
65		GlaxoSmithKline Pharmaceuticals Ltd	10,311.32	2.46	1	326.11
66		Ultratech Cement Ltd	10,095.80	2.40	-1	-103.32
67		Aditya Birla Nuvo Ltd	9,835.56	2.34	0	-124.00
68		Videocon Industries Ltd	9,735.53	2.32	0	-62.98
69		Bank of India	9,704.17	2.31	0	87.73
70		Neyveli Lignite Corporation Ltd	9,688.77	2.31	2	159.38
71		Nestle India Ltd	9,616.02	2.29	3	111.36
72		JSW Steel Ltd	9,558.33	2.28	-1	-9.02
73		Indian Petrochemicals Corporation Ltd	9,539.80	2.27	0	28.57
74		Mahanagar Telephone Nigam Ltd	9,434.25	2.25	-4	-163.80
75		Canara Bank	9,257.80	2.20	0	178.35
76		Aban Offshore Ltd	9,190.17	2.19	0	173.57
77		Financial Technologies India Ltd	9,123.84	2.17	0	253.97
78		Bank of Baroda	8,937.27	2.13	1	229.49
79		Hindustan Petroleum Corporation Ltd	8,897.23	2.12	-1	72.96
80		Dabur India Ltd	8,529.61	2.03	0	-4.31
81		Indiabulls Financial Services Ltd	8,495.34	2.02	4	511.09
82		Indian Hotels Company Ltd	8,494.42	2.02	-1	-20.53
83		Jindal Steel & Power Ltd	8,483.89	2.02	-1	20.01
84		Glenmark Pharmaceuticals Ltd	8,131.54	1.94	-1	-104.45
85		United Spirits Ltd	8,102.30	1.93	-1	35.43
86		Asian Paints Ltd	7,751.28	1.85	1	97.84
87		Crompton Greaves Ltd	7,729.06	1.84	-1	-45.82
88		Hindustan Copper Ltd	7,417.14	1.77	0	-153.64
89		BF Utilities Ltd	7,238.40	1.72	0	-52.92
90		Bharat Forge Ltd	7,148.25	1.70	0	-129.14
91		Sesa Goa Ltd	6,946.61	1.65	0	260.77
92		Sobha Developers Ltd	6,687.64	1.59	4	437.77
93		Mangalore Refinery & Petrochemicals Ltd	6,582.15	1.57	-1	131.47
94		Industrial Development Bank of India Ltd	6,399.67	1.52	1	123.14
95		Essar Oil Ltd	6,381.37	1.52	2	136.74
96		United Phosphorus Ltd	6,369.19	1.52	-3	66.57
97		Jet Airways India Ltd	6,245.40	1.49	1	14.25
98		Parsvnath Developers Ltd	6,219.64	1.48	3	266.89
99		Indian Overseas Bank	6,188.93	1.47	0	111.68
100		Centurion Bank of Punjab Ltd	6,001.06	1.43	0	-62.67
101		Pantaloon Retail India Ltd	5,979.28	1.42	1	67.53
102		Patni Computer Systems Ltd	5,975.85	1.42	-8	-313.90
103		Shipping Corporation of India Ltd	5,915.65	1.41	7	714.23
104		United Breweries Ltd	5,851.54	1.39	-1	-34.57
105		Cummins India Ltd	5,766.75	1.37	1	69.30
106		Century Textiles & Industries Ltd	5,731.15	1.36	-1	12.10
107		Lupin Ltd	5,681.57	1.35	-3	-49.80
108		Adani Enterprises Ltd	5,573.07	1.33	-1	87.50
109		Union Bank of India	5,523.46	1.32	-1	131.33
110		Oriental Bank of Commerce	5,344.01	1.27	-1	121.51
111		Ashok Leyland Ltd	5,255.77	1.25	2	258.15
112		Nicholas Piramal India Ltd	5,224.28	1.24	-1	51.21
113		Mphasis Ltd	5,154.31	1.23	2	212.47
114		Thermax Ltd	4,978.35	1.19	0	-8.34
115		Tata Teleservices Maharashtra Ltd	4,876.59	1.16	3	153.81
116		Godrej Industries Ltd	4,865.17	1.16	-4	-150.30
117		Biocon Ltd	4,848.00	1.15	-1	-72.00
118		Tata Chemicals Ltd	4,749.47	1.13	2	78.51
119		Essar Steel Ltd	4,747.31	1.13	-2	-68.39
120		Colgate Palmolive India Ltd	4,701.95	1.12	1	89.76
121		Wockhardt Ltd	4,684.95	1.12	1	87.00
122		Amtek Auto Ltd	4,677.40	1.11	1	99.74
123		Areva T&D India Ltd	4,667.23	1.11	-4	-11.77
124		Corporation Bank	4,622.35	1.10	0	141.29
125		Tata Tea Ltd	4,565.07	1.09	9	588.23
126		Divis Laboratories Ltd	4,417.26	1.05	-1	-40.03
127		Titan Industries Ltd	4,347.71	1.04	0	64.36
128		Anant Raj Industries Ltd	4,294.16	1.02	0	20.74
129		Yes Bank Ltd	4,286.80	1.02	-3	-12.60
130		IVRCL Infrastructures & Projects Ltd	4,221.16	1.01	3	234.69

Key terms and definitions in stock futures and options trading

What is an option?

A stock option is a contract which gives the buyer the right,
but not the obligation, to buy or sell shares of the underlying
security or index at a specific price for a specified time.
Stock option contracts generally are for 100 shares of the underlying
stock.
There are two types of options, calls and puts.


What is a call option?

A call option gives the buyer the right, but not the obligation,
to buy the underlying security at a specific price for a specified
time.
The seller of a call option has the obligation to sell the underlying
security should the buyer exercise his option to buy.


What is a put option?

A put option gives the buyer the right, but not the obligation,
to sell an underlying security at a specific price for a specified
time.
The seller of a put option has the obligation to buy the underlying
security should the buyer choose to exercise his option to sell.


What is the option premium?

The premium is the price at which the contract trades.
The premium is the price of the option and is paid by the
buyer to the writer, or seller, of the option.
In return, the writer of the call option is obligated to
deliver the underlying security to an option buyer if the call
is exercised or buy the underlying security if the put is exercised.
The writer keeps the premium whether or not the option is exercised.


What is a strike price?

The strike, or exercise, price of an option is the specified share
price at which the shares of stock can be bought or sold by the buyer
if he exercises the right to buy (in the case of a call)
or sell (in the case of a put).


What is an at-the-money option?
An in-the-money option?
An out-of-the money option?

When the price of the underlying security is equal to the strike
price,
an option is at-the-money. A call option is in-the-money if the
strike
price is less than the market price of the underlying security.
A put option is in-the-money if the strike price is greater than
the market price of the underlying security. A call option is
out-of-the-money if the strike price is greater than the market
price of the underlying security. A put option is out-of-the money
if the strike price is less than the market price of the underlying
security.


What is a contract size of an equity option?

The amount of the underlying asset covered by the options contract.
This is 100 shares for one option unless adjusted for a special
event,
such as a stock split or a stock dividend.


What is open interest?

Open interest refers to the number of outstanding option contracts
in the exchange market or in a particular class or series.


What does it mean to be exercised or assigned on an option
transaction?

When you buy an option you have the right to either purchase or
sell stock at a predetermined price. When and if you choose to
purchase or sell stock at that predetermined price you are
said to be "exercising your right".

When you sell an option you now have the obligation to sell or
purchase stock.
You have or may not have to fulfill that obligation.
You are considered to be "assigned" if you are being required to
fulfill that obligation. Typically this occurs when the option is in-
the-money.


What happens to my option if I do nothing?

If you bought a call or put you would lose the premium you paid
for the option plus whatever commissions and fees incurred on that
transaction.
If you sold a call or a put and your option is in-the-money you will
most
likely be assigned and you will have to sell or buy stock.


When can I anticipate being assigned?

You can anticipate being assigned any time your option becomes
in the money. Individual investors may be automatically assigned
or exercised at expiration by The Options Clearing Corporation if
the option is 0.75 or more in the money.
Also, most brokerage firms have rules under which options will
be automatically exercised; check with your broker to determine
which automatic exercise rule may apply.


What is a European-style and American-style option?

American-style is an option contract that can be exercised
at any time between the date of purchase and the expiration date.
Most exchange-traded options are American-style.
All stock options are American-style.
European-style option contracts may be exercised
only on the day before the expiration date.


What is the expiration date?

The last day (in the case of American-style) or the only day
(in the case of European-style) on which an option may be exercised.
For stock options, this date is the Saturday immediately following
the third Friday of the expiration month; however,
brokerage firms may set an earlier deadline for notification of
an option buyer's intention to exercise. If Friday is a holiday,
the last trading day will be the preceding Thursday.


What is the last full day of trading in the Equities, OEX and SPX?
How do they settle?

The last full day of trading for Equities and OEX is the 3rd Friday
of the month. They settle on the close. The last full day of trading
for SPX is the Thursday before the 3rd Friday of the month.
SPX settles on the opening of the 500 stocks that make up the index
on Friday morning. Friday holidays push all of these dates ahead one
day.


What is a strike price and how is it determined?

A strike price is the actual numeric value of the option.
For example, a May option may have strike prices of 45, 50 and 55.
Strike prices are determined when the underlying reaches a certain
numeric value and trades consistently at or above that value.
If, for example, XYZ stock was trading at 49, hit a price of 50
and traded consistently at this level, the next highest strike may be
added.