It’s becoming increasingly difficult to stick to a strategy in Hong Kong’s equity market.

The Hang Seng Index is tracing a pattern that it’s held since early August, rising for a week or two only to then give up most of those gains. The swings are becoming more brutal, hurting bulls and bears alike: chasing momentum in Hong Kong has lost 13% for investors this year.

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For the day, the Hang Seng Index closed up 0.5% after falling by the same amount earlier in the session. Citic Ltd and Tencent Holdings Ltd led gains. Local developers and landlords slipped after starting the session higher. The Hong Kong dollar was little changed.

The Hang Seng Index is tracing a pattern that it’s held since early August, rising for a week or two only to then give up most of those gains

Just last week improving sentiment globally meant the Hang Seng measure joined many of the world’s stock benchmarks in overbought territory. But such optimism, reinforced by signs the US and China were moving toward an agreement on trade, was overturned as local protests turned violent this week. The index fell below the key 27,000 level Monday, dipping below its 100-day moving average. It edged back above it on Tuesday.

“There’s not enough certainty,” said Airy Lau, investment director at Fair Capital Management Ltd. He has no exposure to Hong Kong-listed shares after exiting his positions between May and August. “We’ll see stocks fall a little here, rise a little there. I don’t think investors expect a resolution to the protests any time soon.”

Hong Kong stocks fluctuated between gains and losses as protests extended into Tuesday, blocking roads at lunchtime in the central business district. Volume was about 20% lower than the 30-day average, with many of the city’s finance workers being advised to stay home.

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The gap between peaks and troughs in the Hang Seng index has widened since August, as headlines on trade and protests affected sentiment more than before. Traders rushed to buy volatility on Monday, with the Hang Seng’s version of the VIX surging 21%, the biggest advance in three months. Volume for both put and call options rose to a one-month high.

To Kenny Wen, a strategist at Everbright Sun Hung Kai Co, the best way to play the market is to not play it at all.

“It’s very hard to tell which level is safe now,” Wen said by phone. “Investors should cut their exposure until there is some clarity in the ongoing situation in Hong Kong, as well as the trade talks.”

Beijing's relationship with Washington on trade is especially pertinent for Hong Kong as the city’s biggest stocks derive the majority of their earnings from the Chinese mainland. Increasing uncertainty on both trade and the protests in Hong Kong is likely to keep investors nervous for now.

“If any of those factors gets more negative, the market will test lower ground,” said Louis Tse, managing director at VC Asset Management Ltd. “We don’t know yet.”