Hong Kong (CNN Business) SoftBank's stock is having its worst week since early August.

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.

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