Futures for Brent crude, the international benchmark, are trading more than $20 above last month's lows. Oil's quick return to near-$100-a-barrel levels has already pushed average gas prices at the pump above $4 a gallon and is stoking inflation concerns.

10-year Treasury yields are ticking higher, and investors now see the likelihood of the Fed raising interest rates next Wednesday at just under a quarter, from about 16% at the start of this week.

Equity investors also seem to be more mindful of those risks today, with futures contracts tied to major U.S. indexes slipping after yesterday's chip-stock rally. Today brings earnings from major tech names, including Alphabet, Tesla, and IBM after the bell.