Mr Gilbert exercised 413,000 executive shares options, Aberdeen said, acquiring stock worth nearly £1.8 million.
Taking into account the option exercise price of 59p, Mr Gilbert made a profit of £1.5m.
Mr Gilbert, who founded Aberdeen 31 years ago, sold 241,368 shares netting just over £1m in order to cover the exercise price and his tax and national insurance bill, the fund manager said.
The options were awarded on January 23, 2004 at a time when Aberdeen's shares were trading at just 53.19p.
This was barely a ninth of the price it had been just three years earlier.
But in 2004, the company was still reeling from the stock market crash that came with bursting of the dot.com bubble and was embroiled in the associated split-capital trust scandal.
Aberdeen's share price has only recently regained the lofty heights it attained in 2001. This follows a focus on institutional investment clients and a series of canny acquisitions in the aftermath of the credit crunch culminating in December's agreement to purchase Lloyds Banking Group's Scottish Widows Investment Partnership for £650 million.
Mr Gilbert, who has made a series of multi-million pound share sales in the past few years, now has a holding of 183,865 shares worth £774,000.
However taking into account conditional and unconditional share awards, his holding amounts to more than 5.8 million shares with a paper value of as much as £24.6m.