Bitcoin’s buddy a bad influence: rpt.

Bitcoin soared 488 percent over 13 months ended March 31, captivating both Wall Street pros and millions of Main Street investors.

But roughly half of the incredible run-up in value of the crypto-asset was the result of manipulation, according to a startling research report on Wednesday.

Without manipulation, bitcoin’s rise over the 13 months would have been a much less glossy 245 percent, the report claims.

The manipulation was orchestrated by Bitfinex, a bitcoin exchange with offices in Asia, the report claims, through Tether, a second crypto-asset, which it owns.

Tether, which would be used to purchase bitcoin, would be distributed by Bitfinex when the price of bitcoin sagged on other exchanges, according to the 66-page report from John Griffin, a finance professor at the University of Texas, and Amin Shams, a graduate student.

“Tether seems to be used both to stabilize and manipulate bitcoin prices,” the two claimed in the paper. Tether is tied in value to the US dollar and is backed by a reserve of the currency, Bitfinex claims.

US regulators subpoenaed records from Bitfinex last year to see if it did, indeed, have a reserve of US dollars. No charges have been filed against the exchange and its executives have denied any wrongdoing.

“Bitfinex nor Tether is, or has ever, engaged in any sort of market or price manipulation,” Bitfinex CEO JL van der Velde told Bloomberg in an emailed statement. “Tether issuances cannot be used to prop up the price of Bitcoin or any other coin/token on Bitfinex.”

The report said that Tether had a pattern of being spent on bitcoin at pivotal moments, helping to drive bitcoin to a value close to $20,000 in December. Bitcoin on Wednesday fell to its lowest price since Feb. 6, at $6,250.