As investor concern grows over an information crackdown in China, another key data source has become mysteriously rarer: readouts from meetings of the nation’s 24 most-powerful men.

Since President Xi Jinping secured a precedent-defying third term in October, the Communist Party’s top decision-making body has skipped publishing a statement for three separate months. During the Chinese leader’s second term, it took the party nearly five years to miss the same number of statements.

While there is no public mandate for the Politburo to meet monthly, it has done so for 90% of Xi’s decade-plus tenure, according to a Bloomberg News analysis of government statements.

It’s unclear whether the Politburo failed to convene in November, January and May, or if the elite group discussed sensitive matters it didn’t want to reveal. It’s still possible for state media to release statements on the body’s activities. Sometimes the party releases transcripts of Xi’s remarks months, or even years, later.

The omissions come as Beijing builds a black box around sensitive information, in the wake of growing US scrutiny of its tech industry and economic engagement with Russia. China has in recent months limited access to corporate data, court documents, academic journals and raided expert networks serving businesses, hampering investors’ ability to assess the economy.

“The unintended consequence of this kind of silence, whether it’s data or policy decisions or official announcements, is that people don’t know how to distinguish rumor from official policy,” said Alicia Garcia Herrero, chief Asia Pacific economist at Natixis SA.

“The result is less certainty on policy direction and thus investors potentially holding back or needing to take on more risk,” she added.

While Politburo readouts tend to be formulaic, they provide a rare glimpse into the operations of the secretive body that gathers behind closed doors and publishes no schedules or agendas.

Changes in tone and broad pledges can be enough to send stocks rallying or plunging. Investors dialed back expectations for major stimulus after leaders said that China’s recovery was “better than expected” at the Politburo meeting in April.

Perhaps most-watched are the three Politburo meetings focused on economic policy in April, July, and December. The body has never missed a readout from these sessions throughout Xi’s tenure.

While it’s possible the recent missing readouts are a sign the Politburo is meeting less than usual, official statements show the body held study sessions in January and May. Typically, those events take place on the same day as the broader meeting.

The Politburo has kept the world in the dark before. Last year, it issued its shortest readout of Xi’s rule, and the first to not disclose specific discussion topics, as the Chinese leader headed into the politically sensitive leadership congress. During Xi’s first five years in office, there were seven months without readouts. But while August 2015 had no statement, for example, the month before had two, suggesting the huddle happened slightly earlier.

For now, investors are left guessing what Xi and the powerful group he’s packed with loyalists might have discussed last month.

“At a minimum, there seems to be change in how Politburo meetings are reported, though we need more data points to verify this,” said Adam Ni, publisher of the China Neican newsletter on Chinese politics, who has written previously on missing Politburo readouts.

“At a maximum, it reflects a whole new way of exercising power,” he added, cautioning that more evidence was required to say with confidence what the absence showed.

--With assistance from Yihui Xie and Davy Zhu.