BLSM BlossomHill Therapeutics (BLSM) Insider Trading, Ownership & Congress Trades
Pharma & Biotech · Pharmaceutical preparations · CIK 0001839970
Cluster · 6 insidersActivist 13DC-suite buying · 2
House members buying, 1 year
0
STOCK Act, US House only, disclosed up to 45 days after the trade
Funds added, last quarter
0
13F, latest reported quarter
Conversions, 180 days
14
Codes C/M, not in net · no price filed
What the filings say about BLSM
Insiders, 180 days
+$25.2M net bought
6 buyers
Activist stakes (13D), 180 days
2 filings
Largest: 11.8% of the class
BlossomHill Therapeutics insider trades (Form 4)
Form 4 buys and sells (codes P and S). Grants, option exercises
and conversions excluded.
Over the last 180 days, BlossomHill Therapeutics, Inc. insiders bought a net $25.2M of stock across 7 Form 4 purchases and sales, with 6 insiders buying. Source: SEC Form 4 filings, as of 2026-10-27.
Insider
Filed
Shares
Value
Since filing
Context
- 1 earlier Form 4 trade (code P or S) here by this insider (1 buy), the last on Aug 7, 2026.
- The trade is 2.0% of the 111,412 shares held after it.
- 5 other insiders bought within 30 days.
Insider activity: General Counsel Liptak Vincent Paul bought about $35.2K of BLSM on Aug 10, 2026; 5 other insiders bought within 30 days.Context
- First Form 4 purchase or sale (code P or S) here by this insider on our record.
- The trade is 100.0% of the 700 shares held after it.
- 5 other insiders bought within 30 days.
Insider activity: Chief Financial Officer Keyes Jason A bought about $11.2K of BLSM on Aug 10, 2026; 5 other insiders bought within 30 days.Context
- First Form 4 purchase or sale (code P or S) here by this insider on our record.
- The trade is 8.6% of the 3,614,034 shares held after it.
- 5 other insiders bought within 30 days.
Insider activity: Director Chen Bihua bought about $5.0M of BLSM on Aug 10, 2026, the largest insider purchase at the company on our record; 5 other insiders bought within 30 days.Context
- First Form 4 purchase or sale (code P or S) here by this insider on our record.
- The trade is 100.0% of the 6,000 shares held after it.
- 5 other insiders bought within 30 days.
Insider activity: Director Schmid John P. bought about $96.0K of BLSM on Aug 10, 2026, the largest insider purchase at the company on our record; 5 other insiders bought within 30 days.Context
- First Form 4 purchase or sale (code P or S) here by this insider on our record.
- The trade is 23.0% of the 2,714,279 shares held after it.
- 5 other insiders bought within 30 days.
Insider activity: Director ORBIMED ADVISORS LLC bought about $10.0M of BLSM on Aug 10, 2026, the largest insider purchase at the company on our record; 5 other insiders bought within 30 days.7 transactions on record
Since filing: total return from the first close after the filing to the latest close, dividend-adjusted. Not a forecast.
Context lines are counts over the filings above and returns from our own price history, never a price level. Not investment advice.
Seven facts, ranked against the sector ·
Rank is not a forecast
Insiders
net +$25.2M over 180 days
+$25.2M over 90 days · +$5.0M of it by a 10%+ holder
more than 97% of Pharma & Biotech
Congress
no House purchase disclosed in the last 12 months
Funds
under five funds report holding it
Revenue
no revenue reported in any filing
Margin
no margin: no revenue reported
Buybacks
no share repurchases reported
Short interest
2.7% of the float short (float per yahoo 2026-10-26) · 1.6 days to cover · settled 2026-09-30
below 69% of Pharma & Biotech
The situation: each line is one rule over one dataset
ORBIMED ADVISORS LLC disclosed a 5%+ stake (8.9%) in the last six months.
What changed in the last 30 days
Nothing new filed in the last 30 days
Watch BLSM
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The year, with the filings on it
Total return over 12 months. Each marker is a filing; hover or tap one for the detail.
+2.4%12M
Insider buy13D/G stake
Indexed to 100, dividend-adjusted, not a price chart.
When a name files heavily, the largest trades are drawn first.
Who owns BLSM: institutional holders (13F)
13F holdings, latest reported quarter
SEC 13F
No reported 13F holders
No fund above the reporting threshold listed this stock last quarter. That is a fact, not missing data.
Congress trades in BLSM
No Congress trades reported
No House member has disclosed a trade in this stock. See what Congress is buying.
Activist and 5% holders (13D/13G)
13D: intends to influence · 13G: passive
ORBIMED ADVISORS LLC
Activist 13D · 2026-08-18
8.9%
OrbiMed Capital GP VIII LLC
Activist 13D · 2026-08-18
8.9%
Cormorant Global Healthcare Master Fund, LP
Activist 13D · 2026-08-13
3.13%
Cormorant Global Healthcare GP, LLC
Activist 13D · 2026-08-13
3.13%
Cormorant Private Healthcare Fund III, LP
Activist 13D · 2026-08-13
4.01%
BLSM planned insider sales (Form 144)
No planned-sale notices
No insider has filed to sell. Watch this after a run-up.
Clinical pipeline
2 registered trials, 2 still running (ClinicalTrials.gov).
A status change is dated here weeks before the press release.
1
Phase 1
1 active
1
Multi-phase
1 active
Matched by sponsor name. Trials run under a subsidiary's
own name are not included.
Live price
Daily candles from TradingView, under their licence. No filings marked.
Why this name is on the desk
6 insiders reported buying shares.
The record shows a net $25.2M bought by insiders over 180 days. Each figure is a federal filing, dated the day it went public.
BLSM Stock Sonar score 2/7 axes
Find similar shapesCompare2 of 7 axes scored. Each is a percentile against sector peers (all companies when the sector is thin); higher is better. An unscored axis is unmeasured, not low. How it is scored
BLSM filings, in plain words
Are BlossomHill Therapeutics insiders buying or selling BLSM?
In the 180 days to 2026-10-27, BlossomHill Therapeutics insiders were net buyers, a net $25.2M across purchases and sales reported on Form 4, by 6 buyers.
Read the full summary
In the 180 days to 2026-10-27, BlossomHill Therapeutics insiders were net buyers of BLSM, a net $25.2M across purchases and sales reported on Form 4 by 6 buyers. 6 different insiders reported purchases within the last 90 days, a cluster buy, which is rarer than a single purchase. 2 activist Schedule 13D filings in the last 180 days declared an intent to influence the company, the largest for 11.8% of the class. Each figure is counted from SEC and House filings as of 2026-10-27, dated the day the filing was made public.
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