If the parent had discovered a viable and profitable trading strategy, do you think they would share it here?

I've been out of the loop for a number of years, but I believe there's a serious amount of ML being thrown at predicting time series, so this probably gives you an idea of how money is being made.

I've no idea what the current models look like. I imagine it was all RNNs but maybe transformers have taken over?

If a feature is used by many and has a predictable impact on their behavior it becomes profitable again.

If you act faster on the same feature as everyone else, or you predict the feature accurately, you can anticipate what the market will do in response.

The market often overreacts to new data. So if satellite imagery shows steep decline in parked cars, the stock will be predictably oversold. You can then take a contrarian position (buy the stock before it reverses to the mean).

Some commonly used features by popular public trading bots create predictable market movements, no matter if the feature itself is long-term informative/profitable.

True, but they were just meant as easy examples of non-HFT hedge fund strategies.

yeah but but his point is that hedge funds do things that are non-obvious to extract alpha