Oil briefly tops $115, stock futures wobble

US crude prices briefly rose above $115 a barrel for the first time since 2008 before trading at $113.78 a barrel as refiners refused to buy Russian oil, cutting global energy supplies. Brent crude futures, the international benchmark, rose 1.6% to $114.68 a barrel. Investors worry that a sustained rise in oil prices could herald a combination of slowing growth and higher inflation, known as stagflation.

“The inflationary impact of oil and natural gas surges is clear. Inflation will be more persistent. Interest rates are being pushed up by central banks’ inflation concerns and that will be bad for growth,” said Edward Park, chief investment officer at British investment firm Brooks Macdonald.

“Stagflation is the big concern for 2023.”

European natural gas prices are down 5% after rising this week. Investors fear that natural gas supplies to Europe could be disrupted as a result of the war. According to analysts, about a third of Russian gas exports to Europe flow through Ukraine.

Moscow’s invasion of Ukraine has set in motion broader market volatility. Investors are trying to gauge how avoidance of Russian commodities, including oil, will fuel already elevated inflation and how aggressively central banks will hike rates when faced with additional price pressures and an uncertain economic outlook. Federal Reserve Chair Jerome Powell said Wednesday he would propose a quarter-point rate hike at the central bank meeting in two weeks.

Shares in energy companies, which are likely to benefit from higher oil prices, gained premarket. ConocoPhillips and Occidental Petroleum were each up about 1%. Snowflake shares fell more than 20% premarket after the company issued weaker-than-expected sales guidance. Okta shares fell nearly 5% after the software company issued guidance suggesting aggressive investing would result in larger-than-expected losses in the near term.

The pan-continental Stoxx Europe 600 fell 0.6% on Thursday. Russian stock markets remained closed for the fourth straight day as the government seeks to limit fire selling after also imposing capital controls on the rub.

The London Stock Exchange Group has suspended trading in more than 50 Russian stocks. Index provider MSCI Inc.

and FTSE Russell have announced they will remove Russian stocks from their benchmarks next week, and S&P Dow Jones Indices is considering doing the same.

The ruble fell 13.1% against the greenback on Thursday, to 118 rubles per dollar, according to FactSet.

Traders say the unwillingness of investors and brokers to touch the currency has limited the ease with which they can trade it. Neighboring countries’ currencies have also fallen against the dollar as investors worry about the economic fallout. The Polish zloty fell 1.4% and the Hungarian forint 0.6%.

In US bond markets, the benchmark 10-year Treasury yield rose to 1.866% from 1.862% on Wednesday. Yields and prices move in the opposite direction.

The major equity indices in Asia were broadly higher. South Korea’s Kospi rose 1.6% and Japan’s Nikkei 225 rose 0.7%. China’s Shanghai Composite fell 0.1%.

Write to Caitlin Ostroff at caitlin.ostroff@wsj.com