I think, that would be a good enough fix. There should be no delay on divesting, though. It can always be, that one really needs to divest now. Adding a delay of say, 15 min on Investments would be good. There is no reason besides gambling why you couldn't wait this long for your investment to count.
It won't solve much for mechs.
Anyone will divest when profit will go to 3k or 4k or 5k and nakowa comes to gamble
Everyone will invest when the profit is down (15 min later or before does not change much).
And it will take months for him to recover his loss, unless he invest more now.