It stands for low outlay geared option. A low premium option (specifically a put) which allows the holder to participate in an upside movement with a gradually declining payout. The payout is expressed as the ratio of “the underlying price at expiration minus the strike” to “the underlying price at expiration”. If this ratio is zero or negative, no payout shall be expected. In other words, as this option increases in value (by going in the money), its payout is gradually decreased relative to an otherwise identical option.