Granahan Investment Management, LLC
PERIOD 2026-Q2 (filed 2026-08-14) · SOURCE: SEC EDGAR (PUBLIC)
Holdings as of the 2026-Q2 13F-HR filing (filed 2026-08-14). 13F is disclosed up to 45 days after quarter-end.
What a 13F does — and does not — show
These figures come from Form 13F, a quarterly filing that large US institutional managers must submit to the SEC. It is a useful window, but a partial and lagged one, so read it carefully:
- It is a snapshot, up to 45 days old. A 13F shows what a manager held on the last day of a quarter, filed up to 45 days later — the fund may have traded since.
- Long US-listed stocks only. It excludes short positions, cash, bonds, most derivatives, and non-US or private holdings, so it is not the fund’s whole portfolio.
- Reported 13F value is not assets under management. Every share and concentration figure below is a percentage of the reported 13F value only — not the firm’s total assets.
- It describes, it does not recommend. A large or long-held position is not an endorsement, and none of this is investment advice.
Concentration
Share of reported portfolio value. Long US-listed equity positions as filed; percentages are of reported 13F value, which excludes shorts, cash, non-US and private holdings.
| Tier | Reported value | Share |
|---|---|---|
| Top position | $186M | 6.6% |
| Top 5 | $609M | 21.7% |
| Top 10 | $954M | 34.0% |
Top holdings
| # | Security | Shares | Reported value | % of value |
|---|---|---|---|---|
| 1 | PRCH PORCH GROUP INC added | 12,393,660 | $186M | 6.6% |
| 2 | SIMO SILICON MOTION TECHNOLOGY CO added | 445,752 | $149M | 5.3% |
| 3 | FPS FORGENT POWER SOLUTIONS INC added | 1,807,608 | $101M | 3.6% |
| 4 | INDI INDIE SEMICONDUCTOR INC added | 19,419,892 | $87M | 3.1% |
| 5 | VCTR VICTORY CAP HLDGS INC DEL added | 1,015,343 | $85M | 3.0% |
| 6 | FTAIN FTAI AVIATION LTD trimmed | 293,722 | $79M | 2.8% |
| 7 | MRX MAREX GROUP PLC added | 1,254,283 | $76M | 2.7% |
| 8 | MOD MODINE MFG CO trimmed | 263,572 | $70M | 2.5% |
| 9 | CRS CARPENTER TECHNOLOGY CORP trimmed | 96,981 | $60M | 2.1% |
| 10 | NXT NEXTPOWER INC added | 495,938 | $59M | 2.1% |
| 11 | MGNI MAGNITE INC added | 3,083,211 | $59M | 2.1% |
| 12 | AXON AXON ENTERPRISE INC added | 96,829 | $54M | 1.9% |
Sector mix
Reported 13F value by sector, as a share of the largest positions we rank. Sectors come from company reference data joined to each holding. 12% of this value is not classified to a sector and is excluded from the mix. Long US-listed equity positions as filed.
| Sector | Reported value | Share |
|---|---|---|
| Technology | $630M | 43.8% |
| Industrials | $194M | 13.4% |
| Consumer Cyclical | $161M | 11.2% |
| Communication Services | $101M | 7.0% |
| Healthcare | $92M | 6.4% |
| Financial Services | $85M | 5.9% |
How this filer invests
Reproducible measures computed from the positions in this filer’s own 13F filings — not from any outside estimate.
How concentrated the book is
Across 150 reported positions. Shares are of reported 13F value (long US-listed equity), which is not the firm’s total assets. The concentration index (HHI) is the sum of each position’s squared weight — higher means a book concentrated in fewer names.
How much the book turned over
Between the 2026-Q1 and 2026-Q2 filings, on the stable identity of each holding (share classes combined). New positions and exits are counted by presence; adds and trims by share count, and a share-count change matching a standard split ratio with the value held steady is not counted as either.
Long-term holdings vs. higher turnover
Of its 20 largest reported positions, 7 have appeared in its 5 most recent consecutive quarterly filings (more than a year), and 13 are more recent. This filer holds a mix of longer-term and more recently established large positions.
Notable sizing changes among its long-held positions:
- INDI — share count increased 166%
- AXON — share count reduced 89%
- CRS — share count reduced 75%
- MGNI — share count reduced 70%
- LTH — share count reduced 51%
Directional only, measured over the filer’s largest reported positions across the quarters we track. 13F is a quarter-end snapshot, so a name can be held continuously yet slip in and out of the largest positions; this is a starting question, not a verdict.
Quarter-over-quarter changes — filed 2026-08-14
What changed between the 2026-Q1 and 2026-Q2 13F filings. New positions and exits reflect the tracked snapshot; adds and trims are measured on reported value (split-invariant), and moves under $0.25M are omitted as noise.
Between the 2026-Q1 and 2026-Q2 filings, this filer opened its largest new position in TWST, fully exited FIX, added most to SIMO, and trimmed CRS the most. This describes what the 13F reported — not a recommendation.
New positions 22
- TWST$32M
- QNT$19M
- ARXS$11M
- DYN$8M
- ATEX$7M
- SYRE$7M
Exited 20
- FIX$36M
- SMTC$28M
- SRAD$24M
- STRL$14M
- COMP$14M
- STEP$10M
Largest adds
- SIMO$127M
- PRCH$96M
- LGNZZ$42M
- FPS$40M
- RGEN$35M
- GNRC$33M
Largest trims
- CRS$35M
- AMRC$15M
- RMBS$15M
- LEU$14M
- MOD$11M
- YSS$10M
Portfolio trend
Reported 13F value and position count by filing quarter (independent scales).
Frequently asked
What does Granahan Investment Management, LLC own?
Granahan Investment Management, LLC reported 150 long US-listed equity positions worth $2.8B in its 2026-Q2 13F filing.
What changed in Granahan Investment Management, LLC's portfolio last quarter?
Granahan Investment Management, LLC's 2026-Q2 filing is compared against its prior 13F to identify new positions, exits, and the largest increases and reductions, measured on reported value.
Where does this data come from?
Holdings are parsed from SEC Form 13F-HR filings on EDGAR (public filings). 13F is disclosed up to 45 days after quarter-end and reflects long US-listed equity positions only. Informational, not investment advice.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It is filed up to 45 days after quarter-end, so it is backward-looking — the manager may have traded since — and it covers long US-listed equities only, not short positions, cash, or private holdings. Reading a 13F tells you what a manager owned, not whether you should own it.