MicroStrategy (MSTR), the software developer that has made acquiring bitcoin (BTC) a core value, added to its holding for a seventh week in a row. The company bought 5,262 BTC for a total of $561 million in the week ended Dec. 22 to take its total holdings to 444,262 BTC it said.

Shares of MicroStrategy were down over 4% as markets opened on Monday after the Michael Saylor-owned software enterprise announced its weekly Bitcoin buy, this time of over 5,000 BTC for around $561 million.

MicroStrategy shares have gained more than 400% since the start of the year thanks to investor optimism about the software company's strategy of buying bitcoin as the cryptocurrency repeatedly hits record highs.