You might be able to make a little more than an index fund. You might make less. But if you are going to invest you must choose what you invest in. Not changing your position ever is really just another bet, betting that your current index-fund is the best possible investment. But it might go up might go down. There is always risk in investing.

Think about a casino where your roulette-algorithm somehow gives 0.6 odds for red and 0.4 for black. Should you play? You might still lose everything because odds are just odds. You might win eventually but probably not like "printing money". Your odds of winning would be better than odds of losing. But you might still lose.

If you have money to invest you have to make a choice where to invest it. If you don't make a choice that is one choice as well. Keeping it in your wallet is one investment-choice as well. If you can trade with no tax consequences it would seem to me that sometimes the choice of selling and buying should be a better choice than choosing to do nothing. No?