Insider at

04

Insider transactions

05
0 buys (P) 0 sells (S) Net: $0 + 26 non-open-market transactions below last 12 months, based on the transactions shown below

Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted

No open-market trades on record; showing all filings.

DateTickerCodeSharesPriceValue Owned afterΔ ownA/Dvs now
Nov. 5, 2025 MSM M 36 · · 87 Direct -29.27% Disposed (price as of 2026-10-05)
Nov. 5, 2025 MSM M 221 · · 0 Direct -100.00% Disposed (price as of 2026-10-05)
Nov. 5, 2025 MSM F 93 $86.68 $8,061 612 Direct -13.19% Disposed 49.9% (price as of 2026-10-05)
Nov. 5, 2025 MSM M 36 · · 705 Direct +5.38% Acquired (price as of 2026-10-05)
Nov. 5, 2025 MSM M 221 · · 669 Direct +49.33% Acquired (price as of 2026-10-05)
Nov. 4, 2025 MSM M 10 · · 123 Direct -7.52% Disposed (price as of 2026-10-05)
Nov. 4, 2025 MSM M 232 · · 699 Direct -24.92% Disposed (price as of 2026-10-05)
Nov. 4, 2025 MSM M 27 · · 132 Direct -16.98% Disposed (price as of 2026-10-05)
Nov. 4, 2025 MSM M 227 · · 227 Direct -50.00% Disposed (price as of 2026-10-05)
Nov. 4, 2025 MSM F 88 $86.42 $7,605 448 Direct -16.42% Disposed 50.4% (price as of 2026-10-05)
Nov. 4, 2025 MSM M 10 · · 536 Direct +1.90% Acquired (price as of 2026-10-05)
Nov. 4, 2025 MSM M 232 · · 526 Direct +78.91% Acquired (price as of 2026-10-05)
Nov. 4, 2025 MSM F 92 $86.42 $7,951 294 Direct -23.83% Disposed 50.4% (price as of 2026-10-05)
Nov. 4, 2025 MSM M 27 · · 386 Direct +7.52% Acquired (price as of 2026-10-05)
Nov. 4, 2025 MSM M 227 · · 359 Direct +171.97% Acquired (price as of 2026-10-05)
Nov. 3, 2025 MSM M 15 · · 159 Direct -8.62% Disposed (price as of 2026-10-05)
Nov. 3, 2025 MSM M 192 · · 384 Direct -33.33% Disposed (price as of 2026-10-05)
Nov. 3, 2025 MSM A 884 · · 884 Direct · Acquired (price as of 2026-10-05)
Nov. 3, 2025 MSM F 75 $84.79 $6,359 132 Direct -36.23% Disposed 53.2% (price as of 2026-10-05)
Nov. 3, 2025 MSM M 15 · · 207 Direct +7.81% Acquired (price as of 2026-10-05)
Nov. 3, 2025 MSM M 192 · · 192 Direct · Acquired (price as of 2026-10-05)
July 28, 2020 MSM A 35 · · 411 Direct +9.31% Acquired (price as of 2026-10-05)
May 22, 2020 MSM A 889 · · 889 Direct · Acquired (price as of 2026-10-05)
May 22, 2020 MSM D 889 · · 0 Direct -100.00% Disposed (price as of 2026-10-05)
April 28, 2020 MSM A 38 · · 376 Direct +11.24% Acquired (price as of 2026-10-05)
Feb. 5, 2020 MSM A 230 · · 338 Direct +212.96% Acquired (price as of 2026-10-05)

P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding

Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.

Derivative holdings (Form 4 Table II) Options, RSUs and convertible securities reported on Form 4 Table II.

06
DateTickerSecurityUnderlying Exercise priceExpirationSharesA/D
Nov. 5, 2025 MSM Dividend Equivalent Units Class A Common Stock, $0.001 par value (36) · · 36 Disposed
Nov. 5, 2025 MSM Restricted Stock Units (RSU) Class A Common Stock, $0.001 par value (221) · · 221 Disposed
Nov. 4, 2025 MSM Dividend Equivalent Units Class A Common Stock, $0.001 par value (10) · · 10 Disposed
Nov. 4, 2025 MSM Restricted Stock Units (RSU) Class A Common Stock, $0.001 par value (232) · · 232 Disposed
Nov. 4, 2025 MSM Dividend Equivalent Units Class A Common Stock, $0.001 par value (27) · · 27 Disposed
Nov. 4, 2025 MSM Restricted Stock Units (RSU) Class A Common Stock, $0.001 par value (227) · · 227 Disposed
Nov. 3, 2025 MSM Dividend Equivalent Units Class A Common Stock, $0.001 par value (15) · · 15 Disposed
Nov. 3, 2025 MSM Restricted Stock Units (RSU) Class A Common Stock, $0.001 par value (192) · · 192 Disposed
Nov. 3, 2025 MSM Restricted Stock Units (RSU) Class A Common Stock, $0.001 par value (884) · · 884 Acquired
July 28, 2020 MSM Dividend Equivalent Unit Class A Common Stock, $0.001 par value (35) · · 35 Acquired
May 22, 2020 MSM Options (right to buy) Class A Common Stock, $0.001 par value (889) $83.03 Oct. 21, 2022 889 Acquired
May 22, 2020 MSM Options (right to buy) Class A Common Stock, $0.001 par value (889) $83.03 Oct. 21, 2021 889 Disposed
April 28, 2020 MSM Dividend Equivalent Unit Class A Common Stock, $0.001 par value (38) · · 38 Acquired
Feb. 5, 2020 MSM Dividend Equivalent Unit Class A Common Stock, $0.001 par value (230) · · 230 Acquired

Exercise/conversion price is blank when not applicable (e.g. RSUs).

Initial ownership (Form 3) 18 holdings

07

Securities held when first becoming an insider, per SEC Form 3.

DateTickerSecuritySharesOwnership
Aug. 18, 2025 MSM Class A Common Stock, $0.001 par value 0 Direct
Aug. 18, 2025 MSM Restricted Stock Units (RSU)→ Class A Common Stock, $0.001 par value (221) 221 Direct
Aug. 18, 2025 MSM Restricted Stock Units (RSU)→ Class A Common Stock, $0.001 par value (454) 454 Direct
Aug. 18, 2025 MSM Restricted Stock Units (RSU)→ Class A Common Stock, $0.001 par value (576) 576 Direct
Aug. 18, 2025 MSM Restricted Stock Units (RSU)→ Class A Common Stock, $0.001 par value (931) 931 Direct
Aug. 18, 2025 MSM Dividend Equivalent Units→ Class A Common Stock, $0.001 par value (175) 175 Direct
Jan. 27, 2020 MSM Class A Common Stock, $0.001 par value 1,301 Direct
Jan. 27, 2020 MSM Restricted Stock Units [F1]→ Class A Common Stock, $0.001 par value (159) 159 Direct
Jan. 27, 2020 MSM Restricted Stock Units [F1]→ Class A Common Stock, $0.001 par value (262) 262 Direct
Jan. 27, 2020 MSM Restricted Stock Units [F1]→ Class A Common Stock, $0.001 par value (353) 353 Direct
Jan. 27, 2020 MSM Restricted Stock Units [F1]→ Class A Common Stock, $0.001 par value (528) 528 Direct
Jan. 27, 2020 MSM Restricted Stock Units [F1]→ Class A Common Stock, $0.001 par value (1,474) 1,474 Direct
Jan. 27, 2020 MSM Dividend Equivalent Unit→ Class A Common Stock, $0.001 par value (108) 108 Direct
Jan. 27, 2020 MSM Options (right to buy) [F8]→ Class A Common Stock, $0.001 par value (889) 889 Direct
Jan. 27, 2020 MSM Options (right to buy) [F8]→ Class A Common Stock, $0.001 par value (2,382) 2,382 Direct
Jan. 27, 2020 MSM Options (right to buy) [F8]→ Class A Common Stock, $0.001 par value (3,088) 3,088 Direct
Jan. 27, 2020 MSM Options (right to buy) [F8]→ Class A Common Stock, $0.001 par value (3,122) 3,122 Direct
Jan. 27, 2020 MSM Options (right to buy) [F8]→ Class A Common Stock, $0.001 par value (3,202) 3,202 Direct

Compensation (DEF 14A)

08

Matched by name from proxy statements (DEF 14A) — verify against the filing.

MSM

Fiscal yearSalaryBonusStock awards Option awardsNon-equity incentivePension changeOtherTotal
2025 $312,279 · · · $137,332 · $22,823 $622,362
2020 $279,029 · · · $57,845 · $14,187 $501,661

Figures from the Summary Compensation Table of the company's proxy statement (DEF 14A). Compensation is not a recommendation.