In a filing with the Securities and Exchange Commission on Monday, Tesla ($TSLA@US) revealed that it suffered $101 million in losses on its Bitcoin holdings in 2021. The EV maker said that the fair market value of Bitcoin at the end of 2021 was nearly $2 billion, having invested $1.5 billion in Bitcoin in the 1st quarter. What makes this interesting? Tesla became one of the first big companies in the world to seemingly go all-in on Bitcoin. Aside from its investments, Tesla recently started accepting Bitcoin in its online store, but it retracted the notion after public backlash against the environmental impact of cryptocurrency. Tesla CEO, Elon Musk, has long been a Dogecoin bull as well, with Tesla recently accepting Dogecoin in its online store. Why is Dogecoin still accepted in the Tesla store? It uses a proof of work consensus that uses scrypt technology, thus making it less energy-intensive. At press time, Bitcoin was trading just under $43,000, up 3% on increasing volume and a rising market cap.