I disagree, but I will not ague that point. The biggest issue that retail traders face is themselves, and their failings being reflected in the way they trade. It is not market manipulation etc. Take any system that has positive expectancy, and then put someone who is market ignorant, or has unresolved psychological issues to trade it, and they will fail.
If you have a billion dollars, and you trade only 2%, it is only 20 million. At 20 mio, you may not even have to Iceberg your order, 20 mio is the type of liquidity that gets sucked up pretty fast, and even if you do Iceberg it, you are talking 5 mio a pop anyway, obviously only 4 trades need to go off.
So the Big guys are not as agile really does not hold water. At any rate I have said my piece for now.
The Ever Watchful VIPER