Something silly but that seems to amuse some people is to find trends between USDT and USDC.

It is true that 1:1 parity with the dollar makes them be almost equivalent to one another, but not at the same time.

It is a sort of ARBITRAGE. However, the normal trading ranges, are too thin for the average trader to profit after costs. Nevertheless, there are moments, when, for whatever reason (often political or related to compliance of the issuers to new regulation) some experience remarkable divergences that make the exchange rate interesting.

For instance, when Circle faced problems in 2023, the exchange rate dropped below 0.75, +25% off parity.

Anybody, with the right mindset could have made that much return in a few weeks in a seemingly riskless arbitrage opportunity.

$USDC $FDUSD