@NIX is probably the best to expand on this, but I should note that the graphs above don’t include market share above and below the swap fee changes and capture relatively long periods of time. The fee was set at 0.2% on the stablepools during periods of higher volume/volatility. Therefore, although a good benchmark to analyse pool performance, average daily volume and fee at different swap fees shouldn’t be taken solely into consideration when deciding what fees to set the pools.
Furthermore, the experiment is ongoing and the goal to maximise profit for all LPs in the USDT, USDC and DAI pools is still being pursued, with more data analysis to come in a near future.
Finally, from Proposal: Change stablepool fees USDT/USDC/DAI to 1.0%, 1.0% and 1.5%, respectively