Options which can be exercised any day before or on the day of expiry

Options which can be exercised any day before or on the day of expiry are called as American options, if the options can be exercised only on the last day of expiry, the options is called European.

most US stock options

Typically, most US stock options are American options.

one that can be exercised at any time during the life of the option

An American option is one that can be exercised at any time during the life of the option.

US equity options

US equity options are American-style options.

more flexible allowing for the option to be exercised any time prior to the expiration date

American style options are more flexible allowing for the option to be exercised any time prior to the expiration date.

Options on individual securities available at NSE

Options on individual securities available at NSE are American type of options.

Most call options

Call Options Trading Tip: Also, note that in the U.S. most call options are known as American Style options.

instruments that are overlooked by most investors

American-type options are instruments that are overlooked by most investors but are growing faster than almost any other financial instruments.

Most exchange-traded options in the US

Most exchange-traded options in the US are American options.

Options that can be exercised on or

Options that can be exercised on or before the due date are commonly known as American options.

All optionable stocks and exchange-traded funds (ETFs)

All optionable stocks and exchange-traded funds (ETFs) have American-style options while only a few broad-based indices have American-style options.

All equity options

All equity options are American-style options, but most foreign currency options and CBOE stock index options are European-style options.

the dominant options contracts for stocks and ETFs

American options are the dominant options contracts for stocks and ETFs.

the right but not the obligation to purchase or sell an underlying equity at any time up to a predetermined expiration date for a predetermined amount

We re-consider the pricing problem under the condition ... An American option is the right but not the obligation to purchase or sell an underlying equity at any time up to a predetermined expiration date for a predetermined amount.