Watching yesterday's ridiculous action and reading the comment above from eltopo (There is no regression to the mean. If we're at +5000, we can go to +10000 as likely as to 0.) have made me realize something: while that statement is true, there is a way you can successfully daytrade because while you do not know future rolls, there is some publicly available info about the future. Bear with me:
IF:
A) You know nokawa follows a random walk, up and down, betting close to max bet, until he loses his entire last deposit OR he makes X BTC (for example, yesterday it was 2k + making up for his previous losses, so 5k)
B) You can see what his balance is (people seem to be able to do this, not sure how)
C) You can see when he is depositing again
D) All other betting going on is relatively so small that we can safely ignore it.
THEN:
A strategy where you divest when he is near losing his last deposit and invest when he is near reaching his goal, then you can make the decision to daytrade EV+ with respect to passive investing. This is because when he is near losing his entire deposit, you only stand to gain very little from him losing it all, and a lot to gain if he doesn't; similarly, when he is near his goal, you stand to lose little if he reaches his goal as compared to how much you stand to gain if he dips back down toward losing his latest deposit. Finally, because (somehow) people know how much his balance is and they see when he has incoming deposits, even if you divest and he loses another, say, 500BTC and loses his deposit, there will be a break while he reloads, so you can invest again and start a new "session".
The point is, like dooglus said, the downside to daytrading is that you might miss a huge 30k slide by nakowa at any point. But the problem with this is that you WON'T miss it (if you're paying attention and day trading), because you'll see nakowa lose his whole balance and then see the new deposit coming.
Does this make sense?
No. If he loses his whole balance 1 or 2 or 3 times, there is no reason to believe that with the next deposit his chances are getting bigger to win his losses back. Same applies for his winning streaks: If investors lose several thousands to him, it's possible that he doesn't achieve his goal yet, continues with playing and wins another few thousands.
If investors want to daytrade, let them do it.