BEIJING — After watching a stock-market collapse wipe out $5 trillion of wealth in less than three months last year, Chinese authorities hatched a plan to stem the pain: circuit-breakers that would be triggered by daily declines of 5 percent.

The new system went into effect on Jan. 4. It lasted all of four days. After two harrowing sessions – Monday and Thursday – that tripped the breaker repeatedly and convulsed global markets, officials suspended the system. Although they didn’t explain their rationale, the decision effectively is an acknowledgment that they think the breakers, at least in their current form, are only exacerbating investor anxiety and deepening the selloff. But by flip-flopping on the rule in such a short span, they only added to the sentiment among investors across the world that they’re improvising – and to ill effect – as they try to stabilize markets and shore up a faltering economy.

“They are changing the rules all the time now,” said Maarten-Jan Bakkum, a senior emerging-markets strategist at NN Investment Partners in The Hague. “The risks seem to have increased.”

The China Securities Regulatory Commission announced the suspension on its official microblog account Thursday night. The benchmark CSI 300 Index had plunged 7.2 percent earlier in the day, triggering an automatic shutdown within 30 minutes of the open, as declines in the yuan eroded investor confidence in the world’s second-largest economy.

The circuit-breakers, which halt exchanges for 15 minutes after a 5 percent drop in the benchmark and for the rest of the day after a 7 percent retreat, have been criticized by analysts for exacerbating losses as investors scramble to exit positions before they’re blocked from selling.

The rout – the CSI benchmark has declined 12 percent this week, and the yuan tumbled to a five-year low – has radiated across global equity markets. The Dow Jones Industrial Average average suffered a drop of more than 1 percent Thursday for the third time this week, the yen reached a four-month high and gold surged on haven demand.

Although China’s economy is showing signs of stability after decelerating to its slowest annual pace since 1990, investors are concerned how deftly, or ineptly, the authorities will manage its equities and the currency.

The stock market has gone from boom to bust and back again more times in the past 12 months than most major peers do over the course of a decade.

China’s regulators abandoned the circuit-breaker because “it wasn’t working very well or wasn’t doing the job it was supposed to,” Geoffrey Dennis, head of global emerging-market strategy at UBS Securities, said by phone from Boston. “I think its more of a move to try to improve, a technical adjustment that may end up with a better designed instrument down the road.”