Third Rock Ventures IV, L.P.

Ten-percent owner · MAZE, TNGX

As of 2026-09-27, Third Rock Ventures IV, L.P. has 35 Form 4 transactions on record across 2 companies — 8 in the trailing 12 months.

Everything this person has disclosed to the SEC on Form 4 — across every company they file for — reconstructed from the public record. A filing history, not a tip sheet.

Pattern in the record: open-market sales filed in September in multiple years since 2024 — a recurring calendar cadence, more consistent with scheduled activity than a one-off decision.

Reconstructed holdings

Direct: $450.1MIndirect: $0$450.1Mas of 2026-09-27
  • Direct $450.1M
  • Indirect $0
TNGXdirect13,386,574 sh$333.6M
MAZEdirect4,473,958 sh$116.5M

Reconstructed from this person's own Form 4 filings — the total each filing reported owning afterward, priced at the close on the as-of date shown. A filed position can lag the real one.

Direct and indirect holdings (e.g. through a trust or fund) are tagged separately, as filed.

Trades by company

TNGX · 23 trades
2025-10-23: Sale, 477,401 sh ($4.8M)2025-09-16: Sale, 363,541 sh ($2.6M)2025-09-08: Sale, 86,459 sh ($609K)2025-09-05: Sale, 642,906 sh ($4.5M)2025-08-22: Sale, 302,194 sh ($2.1M)2025-08-19: Sale, 1,100,000 sh ($7.7M)2024-09-13: Sale, 67,400 sh ($710K)2024-09-05: Sale, 75,000 sh ($867K)2024-08-30: Sale, 175,000 sh ($2.0M)2024-08-27: Sale, 25,000 sh ($289K)2024-08-19: Sale, 150,000 sh ($1.5M)2024-08-16: Sale, 135,000 sh ($1.3M)2024-08-01: Sale, 40,000 sh ($392K)2024-07-31: Sale, 100,000 sh ($993K)2024-07-30: Sale, 95,000 sh ($931K)2024-07-26: Sale, 50,000 sh ($492K)2024-07-25: Sale, 100,599 sh ($993K)2024-07-24: Sale, 200,000 sh ($2.0M)2024-07-23: Sale, 125,000 sh ($1.2M)2024-07-22: Sale, 262,740 sh ($2.6M)2024-07-18: Sale, 191,490 sh ($1.9M)2024-07-17: Sale, 550,171 sh ($5.4M)2024-02-20: Sale, 162,500 sh ($1.9M)
MAZE · 12 trades
2025-11-04: Other acquisition, 1,600,000 sh2025-11-04: Other acquisition, 1,600,000 sh2025-11-04: Other acquisition, 1,600,000 sh2025-11-04: Other acquisition, 1,600,000 sh2025-11-04: Other acquisition, 1,600,000 sh2025-11-04: Other acquisition, 1,600,000 sh2025-11-04: Other acquisition, 1,600,000 sh2025-02-03: Conversion, 5,762,788 sh ($0)2025-02-03: Conversion, 950,800 sh ($0)2025-02-03: Conversion, 45,833,334 sh ($0)2025-02-03: Conversion, 9,725,709 sh ($0)2025-02-03: Conversion, 9,166,666 sh ($0)

Filing ledger

DateCompanyActionShares @ priceValueOwnership ΔOwned afterFiling
2025-10-23TNGXSale477,401 @ $10.15$4.8M−3.4% of holding13,386,574Form 4
2025-09-16TNGXSale363,541 @ $7.04$2.6M−2.5% of holding14,363,975Form 4
2025-09-08TNGXSale86,459 @ $7.04$609K−0.6% of holding14,727,516Form 4
2025-09-05TNGXSale642,906 @ $7.00$4.5M−4.2% of holding14,813,975Form 4
2025-08-22TNGXSale302,194 @ $7.00$2.1M−1.9% of holding15,456,881Form 4
2025-08-19TNGXSale1,100,000 @ $7.01$7.7M−6.5% of holding15,759,075Form 4
2024-09-13TNGXSale67,400 @ $10.53$710K−0.4% of holding16,859,075Form 4
2024-09-05TNGXSale75,000 @ $11.56$867K−0.4% of holding16,926,475Form 4
2024-08-30TNGXSale175,000 @ $11.60$2.0M−1.0% of holding17,001,475Form 4
2024-08-27TNGXSale25,000 @ $11.55$289K−0.1% of holding17,176,475Form 4
2024-08-19TNGXSale150,000 @ $10.09$1.5M−0.9% of holding17,201,475Form 4
2024-08-16TNGXSale135,000 @ $9.79$1.3M−0.8% of holding17,351,475Form 4
2024-08-01TNGXSale40,000 @ $9.80$392K−0.2% of holding17,486,475Form 4
2024-07-31TNGXSale100,000 @ $9.93$993K−0.6% of holding17,526,475Form 4
2024-07-30TNGXSale95,000 @ $9.80$931K−0.5% of holding17,626,475Form 4
2024-07-26TNGXSale50,000 @ $9.84$492K−0.3% of holding17,721,475Form 4
2024-07-25TNGXSale100,599 @ $9.87$993K−0.6% of holding17,771,475Form 4
2024-07-24TNGXSale200,000 @ $9.82$2.0M−1.1% of holding17,872,074Form 4
2024-07-23TNGXSale125,000 @ $9.79$1.2M−0.7% of holding18,072,074Form 4
2024-07-22TNGXSale262,740 @ $9.78$2.6M−1.4% of holding18,197,074Form 4
2024-07-18TNGXSale191,490 @ $9.81$1.9M−1.0% of holding18,459,814Form 4
2024-07-17TNGXSale550,171 @ $9.79$5.4M−2.9% of holding18,651,304Form 4
2024-02-20TNGXSale162,500 @ $12.00$1.9M−0.8% of holding19,201,475Form 4
12 award / exercise / gift records — not counted as purchases
DateCompanyActionSharesOwned afterFiling
2025-11-04MAZEOther acquisition1,600,0004,473,958Form 4
2025-11-04MAZEOther acquisition1,600,0004,473,958Form 4
2025-11-04MAZEOther acquisition1,600,0004,473,958Form 4
2025-11-04MAZEOther acquisition1,600,0004,473,958Form 4
2025-11-04MAZEOther acquisition1,600,0004,473,958Form 4
2025-11-04MAZEOther acquisition1,600,0004,473,958Form 4
2025-11-04MAZEOther acquisition1,600,0004,473,958Form 4
2025-02-03MAZEConversion5,762,7886,073,958Form 4
2025-02-03MAZEConversion950,800950,800Form 4
2025-02-03MAZEConversion45,833,3340Form 4
2025-02-03MAZEConversion9,725,7090Form 4
2025-02-03MAZEConversion9,166,6660Form 4

Source: SEC Form 4 filings. Each row links to its original filing.

Research tool, not investment advice — historical frequencies, not recommendations. A product of Marovel Technologies LLC. Full terms.