Financial prediction is vulnerable to training-data leakage: the future must be masked from training data, yet leakage can still occur when trying to predict future events.

“I mean, of course, like one thing that trips up a lot of people is just, you know, leakage of training data and so on. You think, oh, how do I, you know, you want to ideally predict the future before it”

“happens.”

“mask the future in your training data,”

“but there's all kinds of leakage.”