Schafer Jr. disposed of 48,000 shares at $45.71 per share, for a total transaction value of $2.2 million, on August 4.
The transaction involved a same-day exercise of 48,000 stock options at a strike price of $12.00 followed by an immediate open-market sale.
The activity was executed under a Rule 10b5-1 trading plan established on December 16, 2025, indicating a pre-scheduled liquidity event.
Douglas M. Schafer Jr, EVP and CIO of Miami International Holdings, Inc. (NYSE:MIAX), reported a sale of 48,000 shares on August 4, according to an SEC Form 4 filing.
| Metric | Value |
|---|---|
| Transaction value | $2.2 million |
| Shares sold | 48,000 |
| Post-transaction shares (directly held) | 387,414 |
| Post-transaction value | $17.57 million |
Transaction value based on SEC Form 4 weighted average sale price ($45.71); post-transaction value based on August 04, 2026 market close ($45.34).
| Metric | Value |
|---|---|
| Share Price (as of market close 2026-08-05) | $45.96 |
| Market Capitalization | $4.4 billion |
| Revenue (TTM) | $1.5 billion |
| Net Income (TTM) | $142.3 million |
Miami International Holdings is a mid-cap financial services infrastructure provider with a $4.4 billion market capitalization, serving as a critical marketplace operator in U.S. capital markets. The company's diversified platform architecture across options, equities, and futures segments positions it to capture trading volume across multiple asset classes. MIAX maintains competitive advantages through its technology infrastructure, regulatory approvals across multiple asset classes, and established relationships with market participants seeking alternative execution venues.
Schafer runs MIAX's technology, which is the product itself for an exchange operator, so his filing might tempt a closer look, but this is still just a plain plan sale set months ago, and he still kept some 387,000 shares.
More importantly for long-term investors, the systems Schafer oversees carried a record quarter. MIAX grew second-quarter net revenue 35% to $141 million as options volume rose 25% to 11 million contracts a day, and the operating leverage in that technology model pushed adjusted margins above 54%. Gallagher called it "another record quarter" powered by options and the new Bloomberg futures suite. The platform reliability behind that volume is Schafer's remit, which makes his continued large stake more telling than the slice he sold. Still, options market share slipped a touch, to 16.5% from 16.7%, which serves as a reminder that MIAX is defending its turf against bigger exchanges even as volume climbs.
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Jonathan Ponciano has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Miami International. The Motley Fool has a disclosure policy.