Chinese stocks surged for two straight trading days amid suspected government buying, but plunges Monday and Tuesday left the market down nearly 8% for the week.

China’s domestic market became the epicenter of a global selloff, with a five-session crash starting last Thursday triggering steep losses in U.S. and European stocks. Rumors of Beijing’s hand in the market reversed the selling by Thursday, which helped support global shares prices, commodities, and currencies of emerging markets that had been battered.

The Shanghai Composite Index SHCOMP, -1.28% fell for second-straight week and posted a third month of declines, falling 11.8% in August. Hong Kong’s Hang Seng Index HSI, -0.97% lost 12.3% this month, its worst monthly performance since September 2011.

To quiet worries about its slowing growth, Beijing took several easing measures this week to get its economy back in gear, including an interest-rate cut and liquidity injections. The move follows a decision earlier this month to devalue the yuan, which could make exports more competitive, as China struggles to meet its growth target of about 7% for the year.

While Beijing’s measures helped lift global markets, it wasn’t until Thursday that suspicions of government intervention drove the Shanghai Composite up more than 5%.

The momentum then extended into Friday with government appearing to buy again—Shanghai closed up 4.8% at 3,232.35.

Read: Beijing, ‘Loch Ness monster’ eyed in China’s mysterious rally

Volatility on the A-share market was at its highest level on Friday since the selloff that started in June, according to data from Thomson Reuters.

“The [Shanghai] index’s move above 3000 [Thursday] gave it momentum,” said Jacky Zhang, a market analyst at BOC International. A third of some 2,000 firms rose by the 10% daily upward limit set by regulators, he added.

Some even suspected that officials wanted to give investors something to cheer ahead of a parade commemorating the 70th anniversary of World War II next week. China’s markets will be closed Sept 3-4 for a national holiday.

David Cui, a strategist for Bank of America Merrill Lynch, also suspected the China government or its proxies were supporting the market at the end of the week, but that this strategy would ultimately implode.

“If the government sustains buying there are terribly negative consequences, such as impact to [People’s Bank of China’s] credibility and yuan credibility…Any bank can create money out of thin air, which is why confidence is so important,” said Cui. “So if they keep printing money to buy high valued stocks, it will damage yuan credibility.”

“ ‘There’s so much positive in Asia because of lower energy costs.’ ” — Arthur Kwong, BNP Paribas Investment Partners

Elsewhere, most shares in the region rose Friday for a second straight day, buoyed by positive U.S. economic data. A strong reading of U.S. gross domestic product, which expanded 3.7% in the second quarter, up from an initial estimate of 2.3% growth, renewed optimism that the world’s biggest economy could anchor global growth.

The Nikkei Stock Average NIK, +0.17% gained 3%, and South Korea’s Kospi 180721, -2.37% rose 1.6%.

Bucking the trend, the Hang Seng Index finished down 1% on Friday, dragged down by Chinese firms on the market, as international investors remained wary of China’s slowing growth.

Read: China’s economy may be in worse shape than people think

Regional currencies, pressured by fears that a crisis in China would hurt their economies, hit multiyear lows early in the week. They likewise rebounded alongside China stocks.

The Malaysian ringgit USDMYR, +0.29% in particular was up 1% at 4.1870 against the U.S. dollar, having hit a string of successive 17-year lows earlier in the week.

While oil prices in the U.S. rose sharply, prices are still at multi-month lows.

“There’s so much positive in Asia because of lower energy costs,” said Arthur Kwong, head of Asia ex-Japan equities at BNP Paribas Investment Partners, which manages around €552 billion ($620.8 billion) globally.