Optiver Holding B.V.2026-Q2
Optiver Holding B.V.'s 2026-Q2 13F filing captures a market maker aggressively reshaping a book that swelled to 2,757 positions, with heavy buying in index funds and semiconductor names running alongside a decisive retreat from precious metals.
Quick Stats
| Ticker | Action | Value Change |
|---|---|---|
| SPY | Add | +$1.15B |
| MU | Add | +$606.3M |
| GOOG | Add | a notable change |
| GLD | Trim | +$73,991 |
| ON | Trim | -$184,173 — shares were trimmed (real selling), but the dollar value rose because the stock price gained more than the trimmed shares were worth — NOT a buy |
The headline move is SPY, the S&P 500 ETF. The fund actively added to the position, growing it by +$1.15B to $1.16B. Its portfolio weight shifted from 0.00% to 0.31%, a slight dip that reflects the rest of the book expanding around it rather than any step back from the holding. A second, smaller SPY line item also records fresh buying in the quarter. Together, the index ETF anchors the entire disclosure.
MU shows the most dramatic scaling among named stocks. Across multiple reported line items, its weight jumped from 0.07% to 0.22%, and its dollar value grew by +$606.3M to reach $803.5M. Every MU entry carries an add action, meaning share counts genuinely rose rather than the total simply riding a price move. Measured against its starting size, the memory-chip maker ranks among the quarter's biggest active purchases.
Optiver trimmed both GLD and SLV, and more than once. GLD fell by +$73,991 overall, leaving it at 0.00% of the portfolio, while SLV dropped by -$43.3M to 0.00%. Each metals ETF shows up twice in the top changes, and every appearance is a trim, so this is deliberate selling rather than price drift. The move fits a broader rotation visible in the sector data, where hard-asset exposure gave way as technology absorbed more of the book.
This quarter's strangest-looking rows involve ON Semiconductor and AMD. The ON position was trimmed, yet its value rose by -$184,173 to $363,695, lifting its weight from 0.00% to 0.00%. The filing explains it directly: shares were trimmed (real selling), but the dollar value rose because the stock price gained more than the trimmed shares were worth — NOT a buy. An AMD trim line repeats the pattern — genuine selling with the price rally outrunning the value of shares removed — and a third, unnamed position behaves the same way. Read the dollar column alone and all three look like purchases; the action field says otherwise.
By sector weight, yes: Information Technology reached 66.14% of the portfolio, up from 51.51% a quarter earlier. Consumer Discretionary slipped to 11.16% from 16.97%, Financials to 10.85% from 14.06%, and Energy collapsed to 1.82% from 5.3%. Yet the HHI concentration score actually fell, from 0.086346 to 0.073289, because the number of holdings exploded from 2,301 to 2,757. Turnover confirms the frenzy, climbing to 0.342083 from 0.225758 quarter over quarter.
One entry arrives as an outright new_buy: 84615Q903, tagged with a nine-character CUSIP-style identifier rather than a conventional ticker. The filing values it at $759.9M, equal to 0.20% of the portfolio. The disclosure does not reveal what sits behind the code, but it does show Optiver built the stake from zero this quarter and sized it large enough to rank among the top changes.
Optiver operates a high-turnover trading book — turnover of 0.342083, up sharply from 0.225758, spread across 2,757 line items — not a classic buy-and-hold portfolio. Check the action field before trusting the dollar column, because several of this quarter's largest value increases sit on trimmed positions where price gains outpaced the shares sold. The durable takeaways are directional: heavier Information Technology at 66.14%, lighter Energy and precious metals.