Taiyo Yuden Pops 7% on Situational Awareness Stake, But the Fund’s Already Sold

Taiyo Yuden stock rose 7.51% on Wednesday after Situational Awareness disclosed a stake in the Japanese capacitor maker.

The filing looked like fresh buying, but the hedge fund had already sold most of its position weeks earlier.

Situational Awareness’s Taiyo Yuden Stake, Explained

Situational Awareness filed nine change reports on August 12. The AI-focused hedge fund is run by Leopold Aschenbrenner, a former OpenAI researcher. However, the filings came more than a month after the original disclosure deadline.

The reports cover trades made between June and August. Situational Awareness first crossed the 5% disclosure threshold on June 29 with a 5.99% stake. The fund then added shares through mid-July, and its stake peaked at 16.61% on July 22.

The position reversed almost immediately after that. The stake fell to 15.22% by July 30. By August 3, it had dropped to 4.41%, below the reporting threshold.

Margin Calls Forced the Sale

The reversal traces back to Situational Awareness’s own losses, not to Taiyo Yuden’s business. A selloff in AI infrastructure stocks, including SK Hynix and CoreWeave, hit the fund hard in July.

Margin calls then forced the highly leveraged fund to sell its public equity holdings. As a result, assets under management fell from $45 billion to about $10 billion.

Citadel’s fund complex, led by Ken Griffin, bought a large share of the distressed positions at a discount.

A Bounce That May Not Last

Taiyo Yuden makes multilayer ceramic capacitors used in AI data centers. The stock had already climbed about 540% in 2026 through July 1. It then fell on broader worries about AI-related stocks, according to Bloomberg.

Ikuo Mitsui, a fund manager at Aizawa Securities Co., told Bloomberg:

“The stock appears to be reacting positively, at least temporarily, to the large-shareholding report, as the recent correction pushed the share price to less than half its July peak, making the valuation look attractive.”

He added that concerns over MLCC supply and demand could limit how far the rally runs from here.

The episode highlights a lag between headlines and hedge fund filings. Retail traders reacting on August 12 bought into a stake the fund had already cut below 5%.