Asian stocks swung between gains and losses on Thursday as a deepening selloff in semiconductor shares extended losses in the US. Long end of Treasuries dropped, sending yields to their highest levels in almost two decades amid uncertainty over the Federal Reserve’s policy outlook.

The Kospi Index edged 0.8% higher after the government stepped up leveraged ETF curbs following a rout on Wednesday. Samsung Electronics Co. advanced after its earnings beat estimates. SK Hynix Inc. slipped.

A chip selloff deepened on Wall Street, sending a semiconductor gauge down 5.3%. The tech-heavy Nasdaq 100 headed into a technical correction, with the index now down 11% from its record high.

Tech remained in focus as Microsoft Corp. jumped over 8% in extended trading after reporting its fastest cloud-computing growth in four years. Meta Platforms Inc., however, slid over 7% in post-market trading following a disappointing revenue forecast for the current year. Some stability came as futures contracts for Wall Street gauges climbed over 0.3%.

Meanwhile, the Treasury yield curve steepened after the Fed held rates steady. The 30-year yield jumped more than 10 basis points to the highest level since 2007 during the US session. A Bloomberg gauge of the dollar edged lower for a fifth consecutive day on Thursday.

Fed Chair Kevin Warsh said the decision to leave rates unchanged wasn’t a sign of inertia at the central bank and that markets would be free to chart their own course based on economic signals. Three of the Fed’s 12 voting officials dissented in favor of a rate increase, highlighting persistent concerns over inflation.

The lack of updated policy guidance, combined with a divided committee, left investors with little clarity on the path for interest rates. That uncertainty is likely to keep volatility elevated across bond markets as traders parse incoming inflation and economic growth data for clues on the Fed’s next move.

“There is very little to hang your head on in the markets,” Torsten Slok, chief economist at Apollo Global Management, told Bloomberg Television. “It was also a little bit complicated to figure out what was the basis of the decision today,” he said, adding that the Fed’s abandonment of guidance is fueling historic bond market volatility.

Elsewhere, South Korea pledged additional measures to stabilize the stock market and curb retail access to leveraged exchange-traded funds after a rout that wiped billions of dollars off investors’ holdings.

That came after the Kospi Index cratered again Wednesday, extending the decline in the nation’s key equity index this month to a record 33%.

Brent crude edged lower early Thursday as Axios reported that the US military is conducting air strikes on Iran. Oil has whipsawed this month as the US and Iran went from escalation to efforts at diplomacy, and now back to trading military fire.

Traders remain focused on diplomatic moves to end the war, as well as signs that flows through key chokepoints remain compromised. The so-called call skew for Brent, or the premium traders pay for options betting on further price gains, jumped to the highest level since late April.

The global benchmark is also experiencing reduced liquidity ahead of its expiry on Friday, contributing to exaggerated price moves.

“We remain exceedingly skeptical that we are on the brink of a major diplomatic breakthrough that will resolve the nuclear standoff that started the war,” RBC Capital Markets LLC analysts including Helima Croft said in a note. “The ongoing threat of missiles, mines, drones, and Tehran tolls will keep a significant portion of the shipping market on the sidelines,” they added.