Musk's Bitcoin investment follows months of Twitter talk

FILE PHOTO: SpaceX founder and chief engineer Elon Musk looks at his mobile phone during a post-launch news conference to discuss the SpaceX Crew Dragon astronaut capsule in-flight abort test at the Kennedy Space Center in Cape Canaveral, Florida, U.S. January 19, 2020. REUTERS/Joe Skipper/File Photo

(Reuters) - Tesla's TSLA.O $1.5 billion Bitcoin investment unveiled on Monday may not surprise CEO Elon Musk's followers on Twitter, where he has shown himself as a major proponent of the soaring cryptocurrency.

The announcement of Tesla's investment, buried in Tesla's 2020 annual report, follows months of tweets by Musk related to cryptocurrencies including Bitcoin BTC=BTSP, sometimes helping fuel its rally.