Crypto exchanges Huobi and OKX benefited after rival Binance curbed a zero-fee promotion and shed market share in the spot trading of digital assets, according to data from research company Kaiko.

Binance’s share of spot-trading volumes fell to 51% by May 6 from 73% just before the popular promotion was mostly scrapped on March 22. Huobi’s hit 10% from 2% and OKX’s 9% from 5%. South Korean platforms also saw their share increase, to almost 14% from a little under 8%, the Kaiko figures show.

The shakeup could pose another challenge for Binance’s founder Changpeng Zhao. His business faces intensifying regulatory heat, particularly in the US.

The US crackdown “has led to users worrying about the safety of their funds and that’s the reason they are diversifying into other centralized exchanges,” said Cici Lu, founder of Venn Link Partners, a blockchain adviser.

Zhao has repeatedly taken to Twitter to say customer funds are safe. Trust in the digital-asset sector is low after last year’s crypto rout and FTX’s blowup.

A Binance spokesperson said the drop in market share isn’t as great as some of their modeling had projected, adding “our primary objective right now is to mature our existing products and services and continue investing in our compliance processes to prepare for a new era of regulatory certainty.”

While cryptoassets have made a partial recovery in 2023 from a $2 trillion rout, volumes and liquidity remain depressed after investors fled the sector.