MicroStrategy has purchased an additional 5,262 bitcoins, continuing its buying spree for the 7th consecutive week.The company sold $561 million worth of shares to fund the purchase, bringing its total bitcoin holdings to 444,262, valued at $27.7 billion.MicroStrategy's bitcoin buying strategy involves leverage, posing risks if the crypto declines significantly.While MicroStrategy has seen significant gains from its bitcoin bet, a decline in the cryptocurrency could put the company at risk.