MIAX Miami International Holdings, Inc.

NYSE
$41.47

Miami International Holdings, Inc. (MIAX) Insider Activity

What the officers, directors and large holders did with their own shares. Only open-market purchases and sales count toward the totals — grants, option exercises and shares withheld for tax are compensation mechanics, not decisions, and they're listed separately below.

Insider signal Bearish Selling ran elevated versus MIAX's own trailing one-year pace, with 99% of sale value under a prearranged plan.
Cluster activity 0 buyers in the last 30 days 0 buyers in the last 90 days 10 sellers in the last 90 days
Insiders buying
0
0 transactions
Insiders selling
10
29 transactions
Purchases
$0
0 shares
Sales
$35.4M
833,496 shares
Net activity
-$35.4M
purchases less sales

How much of that selling was preplanned? 99% planned / 1% discretionary

10b5-1 plan sales $35.2M 28 transactions · 827,951 shares
Discretionary sales $230.6K 1 transaction · 5,545 shares

Largest single sale: $6.2M.

Where they traded

Buy Sell Dot area is proportional to transaction value.

Last open-market purchase: March 5, 2026 .

Recent open-market activity

Date Insider Role Action Shares Price Value Held after
Gallagher Thomas P. Chairman & CEO Sell 10b5-1 47,000 $42.43 $2.0M 1,423,275 −3.2% of holding
Deitzel Edward EVP, CRO, CCO MIAX Exchanges Sell 10b5-1 11,000 $42.21 $464.3K 119,601 −8.4% of holding
Schafer Douglas M. JR EVP and CIO Sell 10b5-1 48,000 $40.48 $1.9M 387,414 −11% of holding
Comly Barbara J. EVP, GC & Corporate Secretary Sell 10b5-1 44,445 $40.49 $1.8M 839,564 −5% of holding
Teekell Judson Gray Director Sell 5,545 $41.58 $230.6K 81,000 −6.4% of holding
Teekell Judson Gray Director Sell 10b5-1 3,000 $40.89 $122.7K 69,251 −4.2% of holding
Gallagher Thomas P. Chairman & CEO Sell 10b5-1 149,700 $41.13 $6.2M 1,423,275 −9.5% of holding
Emmons Lance EVP and CFO Sell 10b5-1 35,000 $42.83 $1.5M 86,538 −28.8% of holding
Schwarzkopf Cynthia Director Sell 10b5-1 5,000 $42.85 $214.3K 88,545 −5.3% of holding
Gallagher Thomas P. Chairman & CEO Sell 10b5-1 48,334 $45.69 $2.2M 1,723,275 −2.7% of holding
Schafer Douglas M. JR EVP and CIO Sell 10b5-1 48,000 $45.71 $2.2M 387,414 −11% of holding
Comly Barbara J. EVP, GC & Corporate Secretary Sell 10b5-1 44,445 $45.69 $2.0M 882,984 −4.8% of holding
Jayabalan Harish EVP, CISO and CRO Sell 10b5-1 20,000 $45.90 $918.0K 78,065 −20.4% of holding
Deitzel Edward EVP, CRO, CCO MIAX Exchanges Sell 10b5-1 11,000 $45.78 $503.6K 119,601 −8.4% of holding
Teekell Judson Gray Director Sell 10b5-1 3,000 $45.79 $137.4K 72,251 −4% of holding
Eckert Kurt M. Director Sell 10b5-1 1,063 $45.80 $48.7K 149,612 −0.7% of holding
Schwarzkopf Cynthia Director Sell 10b5-1 5,000 $42.00 $210.0K 88,545 −5.3% of holding
Gallagher Thomas P. Chairman & CEO Sell 10b5-1 70,000 $42.52 $3.0M 1,723,275 −3.9% of holding
Comly Barbara J. EVP, GC & Corporate Secretary Sell 10b5-1 28,000 $41.98 $1.2M 882,984 −3.1% of holding
Gallagher Thomas P. Chairman & CEO Sell 10b5-1 28,228 $42.27 $1.2M 1,723,275 −1.6% of holding
Gallagher Thomas P. Chairman & CEO Sell 10b5-1 41,772 $42.09 $1.8M 1,723,275 −2.4% of holding
Jayabalan Harish EVP, CISO and CRO Sell 10b5-1 20,000 $42.12 $842.4K 78,065 −20.4% of holding
Brown Shelly EVP, Chief Strategy Officer Sell 10b5-1 16,000 $42.13 $674.1K 353,990 −4.3% of holding
Deitzel Edward EVP, CRO, CCO MIAX Exchanges Sell 10b5-1 11,000 $42.04 $462.4K 119,601 −8.4% of holding
Schafer Douglas M. JR EVP and CIO Sell 10b5-1 48,000 $41.22 $2.0M 387,414 −11% of holding
Comly Barbara J. EVP, GC & Corporate Secretary Sell 10b5-1 28,000 $41.22 $1.2M 882,984 −3.1% of holding
Eckert Kurt M. Director Sell 10b5-1 5,250 $39.35 $206.6K 149,612 −3.4% of holding
Teekell Judson Gray Director Sell 10b5-1 3,000 $40.00 $120.0K 75,251 −3.8% of holding
Brown Shelly EVP, Chief Strategy Officer Sell 10b5-1 4,714 $44.23 $208.5K 316,714 −1.5% of holding

Form 4s are due within two business days of a transaction, so this is close to real time — unlike the quarterly 13F data on the Institutional tab. A single large sale often reflects a prearranged 10b5-1 plan rather than a fresh view, so read a pattern of sales rather than any one of them.