South Korea, Indonesia and Philippine stocks slid more than 1% on Friday after US futures fell deeper into the red, leaving already unnerved investors unsure about taking on riskier bets.

Indonesian shares are headed for their seventh session of losses and their worst week since March, falling nearly 7%, while stocks in South Korea and the Philippines will mark a fourth session in the red if losses hold.

It has been a frenzied week in equity markets, with retail investors taking on hedge fund short positions, and that has spilled over into Asia just as COVID-19 vaccine rollouts have run into delays and the global economic recovery looks more uncertain.

There were also concerns stemming from China's central bank draining more cash this week than over the last three, which put investors on edge as to whether the supportive policy environment could be waning. It injected 100 billion yuan on Friday, somewhat easing those concerns.Stocks in Shanghai edged 0.2% higher. "Investors should be looking through wild swings in several speculative US stocks and stay focussed on fundamentals," said Wei Liang Chang, a macro strategist at DBS Bank.

But he added that "some precautionary deleveraging is still likely warranted" amid higher volatility.

A Wall Street rebound overnight and US economic data that was not as bad as feared improved risk appetite early in Asian trading hours, which put the dollar on the back foot. The region's currencies stuck to tighter ranges with the especially hard-hit won gaining 0.3%.

The South Korean currency has lost more than 1% so far this week, but stocks have been worse off, falling more than 4% so far and heading for their worst week in about three months.

Asia's retail investors, emboldened by the meteoric rise of US videogame retailer GameStop, are taking on short sellers and making brokers worried enough to cut off margin lending.

US futures fell around 1% into Asia's afternoon trading hours.

"I think its best to be very cautious into the weekend as retail gains could trigger more hedge fund pain. With China tightening it bleeds through all Asia-sensitive risk assets," Stephen Innes, the chief global markets strategist at Axi, said in a note.

Investors in India and Thailand will also be gearing up for central bank policy meetings next week. Barclays expects policymakers to maintain rates.