A tool used by China exporters to get their hands on the yuan temporarily has hit a record, a sign they may be reluctant to permanently transfer their dollar holdings into the local currency.

Chinese firms swapped a record $30.5 billion for yuan via onshore banks last month, according to data released Friday by the State Administration of Foreign Exchange that goes back to 2015. Through such trades, companies can access yuan for their operational cash demands without abandoning their dollar holdings since the currencies can be swapped back at a future date.

The appeal of holding dollars remains strong for some companies in China despite a recent reduction in the rate of dollar deposits. US dollars still offer a yield of around 5.7% for China’s onshore firms, versus less than 3% for yuan deposits, while the prospect of more monetary easing by the central bank is weighing on the outlook on the local currency.

Some exporters became less willing to hold dollar deposits after major Chinese banks were guided to lower their onshore interest rates for corporate clients, according to traders who declined to be named discussing private information.

China’s currency is on track for its first monthly gain in four in July on Monday, rebounding from an eight-month low as Beijing intensified its actions to boost business confidence and the central bank took measures to curb currency weakness. Still, sentiment remains fragile after a slew of recent economic data disappointed.

“While an improvement in sentiment towards the growth outlook would support the exchange rate, we expect other factors to continue to weigh on the yuan,” Goldman Sachs Group Inc. strategists including Danny Suwanapruti wrote in a weekend note. The unfavorable interest—rate spread between China and the US “may widen further as the People’s Bank of China is expected to cut interest rates to facilitate economic growth.”