> If market followed rational logic, you could pre-calculate which stocks will be what price and never lose money.
The fundamentals are unpredictable, so even a perfectly rational planning (suppose such thing could exist) would lose money sometimes. Not in the long run, but long run doesn't matter if a single wrecked ship can wreck you.
You're just being pedantic. To a sufficient advanced being (eg God), the whole universe is rational/calculable/etc. Are you the type who says "you're wrong! It's 9:01" when someone says it's 9?
(Stock) market is, by definition, irrational. If you are scared of solvency, sell and hold money and/or gold.