MIAX's Revenue Jumped 35% to a Record. Here's What to Know About Its Insider Activity

Barbara J. Comly, EVP, GC & Corporate Secretary of Miami International Holdings, Inc. (NYSE:MIAX), sold 44,445 shares of common stock on August 4, as disclosed in a recent SEC Form 4 filing.

Transaction summary

Metric	Value
Transaction value	$2.03 million
Shares sold	44,445
Post-transaction shares (directly held)	882,984
Post-transaction value	$40.03 million

Transaction value based on SEC Form 4 weighted average sale price ($45.69); post-transaction value based on the August 4 market close ($45.34).

Key questions

• What was the mechanical structure of this transaction?
  The transaction was a conversion-and-sale event where Barbara J. Comly exercised 44,445 options at $12.00 per share and immediately sold the resulting shares under a pre-arranged Rule 10b5-1 plan.
• What is the insider's remaining exposure to the company?
  Following this sale, the insider maintains a substantial equity position of about 883,000 directly held shares and also holds 88,889 derivative securities, ensuring continued interest in the company's long-term performance.
• How did the execution price align with the broader market on the trade date?
  The shares were sold at a weighted average price of $45.69, which was slightly higher than the $45.34 market close on the August 4 transaction date.
• What does the adoption date of the trading plan indicate?
  The Rule 10b5-1 plan was adopted on December 18, 2025, more than seven months prior to this execution, establishing that the trade was planned well in advance of the current market environment.

Company Overview

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

Company Snapshot

• Miami International Holdings operates a diversified marketplace ecosystem that provides trading venues for options, futures, and cash equities, generating revenue through transaction fees, market data services, and technology licensing across its MIAX Options, MIAX Pearl, MIAX Emerald, MIAX Sapphire, MIAX Pearl Equities, and MIAX Futures platforms.
• The company generates revenue through a transaction-based model, capturing fees from trading volume across its multiple exchange platforms, supplemented by ancillary revenue streams, including market data dissemination, connectivity services, and regulatory fees.
• The company serves institutional investors, retail traders, market makers, and broker-dealers seeking access to diversified trading venues for options, equities, and futures products in the United States capital markets.

Miami International Holdings is a mid-cap financial services infrastructure provider with a $4.4 billion market capitalization that operates 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.

What this transaction means for investors

Comly exercised long-held options struck at $12 and sold near $46 under a plan set back in December, the kind of decade-old grant an executive cashes once it is deeply in the money (and before an expiration, which in this case is in less than two years). Plus, she’s one of multiple MIAX insiders to run the same play in the same window. When several leaders sell at once on preset plans, the timing could just reflect an open trading window after earnings, rather than a shared verdict. Overall, Comly kept roughly 883,000 shares, so her position is barely touched.

MIAX’s latest results are much more important for investors to scrutinize, and they’re solidly strong. The firm grew second-quarter net revenue 35% to $141 million as options volume rose 25% to 11 million contracts a day, and it cleared a long-running Nasdaq lawsuit with a settlement it has since paid. CEO Thomas Gallagher said the "model's operating leverage drove record margins," which is the real engine here, since profits are climbing faster than revenue. That leverage cuts both ways, though, because much of the quarter's surge rode elevated options volume that management itself expects to cool, warning that revenue per contract should revert toward prior levels in the second half. Keep an eye on how that pans out in the coming quarters, but for now, the firm, which went public just one year ago, is clearly riding on strong momentum.

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.