Last week was one of the best of the year for Bitcoin<\/a> (BTC)<\/strong>, with a surge of over 10%<\/strong>. Several factors explain this meteoric rise, including massive purchases by companies and exchange-traded funds<\/strong> (ETFs) in the United States.<\/p>\n\n\n\n Not content with filling their treasury reserves with bitcoins, companies accelerated their investments even further this week. Japanese group Metaplanet<\/strong> acquired an additional $615 million worth of BTC<\/strong>, becoming the fourth largest publicly-traded holder of the cryptocurrency. In total, thirteen companies strengthened their Bitcoin<\/a> exposure, amounting to more than $1.2 billion<\/strong>.<\/p>\n\n\n\n