NAMS NewAmsterdam Pharma Company N.V.

NASDAQ
$22.36

NewAmsterdam Pharma Company N.V. (NAMS) 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.

30D 90D 6M 1Y
Insider signal In line Selling ran in line with NAMS's own trailing one-year pace, with 5% of sale value under a prearranged plan.
Cluster activity 0 buyers in the last 30 days 0 buyers in the last 90 days 3 sellers in the last 90 days
Insiders buying
1
1 transaction
Insiders selling
6
42 transactions
Purchases
$15.6K
660 shares
Sales
$62.0M
1,920,233 shares
Net activity
-$62.0M
purchases less sales

How much of that selling was preplanned? 5% planned / 95% discretionary

10b5-1 plan sales $3.3M 5 transactions · 100,000 shares
Discretionary sales $58.7M 37 transactions · 1,820,233 shares

Largest single sale: $14.8M.

Where they traded

Buy Sell Dot area is proportional to transaction value.

Last open-market purchase: September 15, 2025 — 1.0 years ago, by Topper James N .

Recent open-market activity

Date Insider Role Action Shares Price Value Held after
Smither John W Director Sell 1,600 $25.32 $40.5K 8,760 −15.4% of holding
Kastelein Johannes Jacob Pieter Chief Scientific Officer Sell 125,000 $26.91 $3.4M 69,302 −64.3% of holding
Kooij Louise Frederika 3 fills Chief Accounting Officer Sell 105,000 $30.34 $3.2M 59,153 −64% of holding
Kooij Louise Frederika 2 fills Chief Accounting Officer Sell 40,000 $30.20 $1.2M 24,653 −61.9% of holding
Kooij Louise Frederika Chief Accounting Officer Sell 65,000 $35.69 $2.3M 24,353 −72.7% of holding
LANGE LOUIS G 2 fills Director Sell 44,619 $30.42 $1.4M 10,806 −80.5% of holding
Kastelein Johannes Jacob Pieter Chief Scientific Officer Sell 101,409 $30.29 $3.1M 69,302 −59.4% of holding
Kastelein Johannes Jacob Pieter Chief Scientific Officer Sell 94,124 $30.32 $2.9M 69,302 −57.6% of holding
LANGE LOUIS G Director Sell 28,186 $29.41 $829.0K None left
Kastelein Johannes Jacob Pieter Chief Scientific Officer Sell 104,467 $30.30 $3.2M 69,302 −60.1% of holding
Davidson Michael H. Chief Executive Officer Sell 443,707 $33.25 $14.8M 174,144 −71.8% of holding
Davidson Michael H. 2 fills Chief Executive Officer Sell 183,332 $33.71 $6.2M 477,783 −27.7% of holding
Davidson Michael H. 3 fills Chief Executive Officer Sell 58,253 $35.30 $2.1M 471,595 −11% of holding
Davidson Michael H. 2 fills Chief Executive Officer Sell 64,708 $36.15 $2.3M 463,020 −12.3% of holding
Kastelein Johannes Jacob Pieter 2 fills Chief Scientific Officer Sell 45,481 $35.31 $1.6M 84,289 −35% of holding
Kooij Louise Frederika Chief Accounting Officer Sell 32,612 $31.80 $1.0M 24,353 −57.2% of holding
Kooij Louise Frederika Chief Accounting Officer Sell 39,816 $32.62 $1.3M 24,353 −62% of holding
Kooij Louise Frederika 2 fills Chief Accounting Officer Sell 34,400 $32.78 $1.1M 24,662 −58.2% of holding
Kooij Louise Frederika 2 fills Chief Accounting Officer Sell 38,172 $33.75 $1.3M 37,120 −50.7% of holding
Somaiya Mayur Ian 2 fills Chief Financial Officer Sell 10b5-1 39,784 $33.59 $1.3M 82,744 −32.5% of holding
Somaiya Mayur Ian 3 fills Chief Financial Officer Sell 10b5-1 60,216 $31.96 $1.9M 117,698 −33.8% of holding
Davidson Michael H. Chief Executive Officer Sell 11,582 $0.00 $0 378,859 −3% of holding
Kastelein Johannes Jacob Pieter Chief Scientific Officer Sell 6,000 $33.25 $199.5K 73,481 −7.5% of holding
Somaiya Mayur Ian Chief Financial Officer Sell 5,118 $33.25 $170.2K 32,882 −13.5% of holding
Kooij Louise Frederika Chief Accounting Officer Sell 2,647 $33.25 $88.0K 12,353 −17.6% of holding
Kooij Louise Frederika Chief Accounting Officer Sell 43,872 $35.30 $1.5M 15,000 −74.5% of holding
Kooij Louise Frederika Chief Accounting Officer Sell 26,011 $35.68 $928.1K 15,000 −63.4% of holding
Kooij Louise Frederika Chief Accounting Officer Sell 75,117 $36.21 $2.7M 15,000 −83.4% of holding
Topper James N Director Buy 660 $23.70 $15.6K 3,028,524

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.