Major bitcoin corporate backer MicroStrategy will borrow $600 million to buy more of the currency, it said on Tuesday, as the cryptocurrency surged past $50,000 in value.

Shares of MicroStrategy, the world's largest publicly traded business intelligence company, rose more than 4% on the news, adding to their meteoric 580% surge in the past year.

The company, whose Chief Executive Officer Michael Saylor has become one of the most vocal proponents of bitcoin, spent last year steadily amassing more of the currency after making its first investment in August.

MicroStrategy said last week that it views its bitcoin coffers as long-term holdings and does not plan to regularly trade in the currency or to hedge or enter into derivative contracts.

MicroStrategy owns close to 72,000 bitcoin, a regulatory filing showed on Feb. 2, valuing its bitcoin holdings at about $3.6 billion, according to a Reuters calculation.

Elon Musk's Tesla Inc provoked a new round of hype around the currency earlier this month by revealing it had purchased $1.5 billion of bitcoin, adding to a handful of US companies holding it on their balance sheets.

MicroStrategy also sold notes worth $650 million in December to buy bitcoin.

Many cryptocurrencies have struggled to win the trust of mainstream investors and the general public due to their speculative nature and potential for money laundering.

However, major firms such as asset manager BlackRock Inc , credit card giant Mastercard Inc and payments companies Square and PayPal, have backed certain cryptocurrencies in recent weeks.

BNY Mellon last week said it formed a new unit to help clients hold, transfer, and issue digital assets.