Tesla has acquired around $1.5 billion in Bitcoin under an investment policy at the electric car maker headed by Elon Musk, and it plans to begin accepting the digital currency as payment for vehicles soon. But the disclosure also raises questions about Tesla CEO Elon Musk’s recent tweets on Twitter about bitcoin.

The California company revealed the new strategy in a filing with the U.S. Securities and Exchange Commission early Monday, saying its investment in digital currency and other “alternative reserve assets” may grow.

“The moves raised immediate questions around CEO Elon Musk’s behavior on Twitter recent weeks, where he has been credited for increasing the prices of cryptocurrencies like bitcoin and dogecoin by posting positive messages that have encouraged more people to buy the digital currencies,” CNBC reported.

“Two weeks ago, the billionaire Tesla owned added the hashtag #bitcoin to his Twitter bio, in a move that helped to briefly push up the price of the cryptocurrency by as much as 20%. Two days later, he said on the social medial chat site Clubhouse: ‘I do at this point think bitcoin is a good thing, and I am a supporter of bitcoin.'”

Bitcoin spiked 14% and appeared to briefly hit a new all-time high. Shares of Tesla moved higher as well.

In its fourth quarter earnings report last month Tesla said it had cash and cash equivalents of $19.4 billion.