SoftBank's stock is having its worst week in nearly three months

The stock is down 1.5% Friday morning, putting SoftBank on pace for its fourth straight day of losses. Bloomberg reported early Friday, citing anonymous sources, that the Japanese tech company is planning to take a writedown to its Vision Fund of at least $5 billion to reflect the sinking valuation of holdings like WeWork and Uber. SoftBank did not immediately respond to a CNN Business request for comment.

Earlier this week, SoftBank announced a massive WeWork bailout.

SoftBank is down nearly 7% this week. That's the worst week for the stock since the first full week of August, when it closed down nearly 10%.

Asian markets, meanwhile, opened mostly lower Friday.

Japan's Nikkei was up 0.1% in early trading, though pulled back a little bit to trade down 0.1%. South Korea's Kospi edged down about 0.1%, but recovered some to trade flat. Hong Kong's Hang Seng slumped 0.5%. China's Shanghai Composite fell 0.6%.

US stock futures were mixed during Asian trading hours. The Dow was down more than 0.1%, while the S&P 500 was nearly flat. The Nasdaq was up slightly.