(Reuters) - Grayscale Bitcoin Trust recorded $1.9 billion in outflows last week, tipping the group of U.S. spot bitcoin exchange-traded funds (ETFs) into net outflows for the week ending March 22, according to data from BitMEX Research.

While there has been buying interest in new funds from BlackRock, Fidelity Investments and others since the U.S. Securities & Exchange Commission approved the new cryptocurrency ETFs in January, it was not enough to offset selling by Grayscale holders last week, the data showed.