Lately, when looking at charts of stablecoin supply and ETF capital flows, the comment section always attributes it with one phrase: it's stable, it's about to take off.

To put it simply, correlation does not equal causation; an increase in stablecoins could mean new entry capital, or it could just be repositioning, market making, or waiting for redemption;
ETF inflows might also be hedging, rebalancing, or slowly spreading out, not necessarily immediately transmitted to the market.

I personally review two things: the direction of new supply/net redemptions, and whether spot trading/on-chain transfers are expanding simultaneously;
if they are not synchronized, I treat it as noise, follow the usual rules, and don't chase the story based on intuition.
Recently, with testnet incentives and point system expectations heating up again, people are guessing daily whether the mainnet will issue tokens,
the result is a spike in on-chain activity, stablecoins bouncing between addresses, looking lively but not necessarily indicating new funds.
Anyway, I’d rather miss it than treat a chart as a script.