RTW INVESTMENTS, LP
"13F equity value" = market value of this filer's US-listed long equity positions only. It excludes cash, bonds, non-US and short positions, so it understates a fund's true assets under management — often by a lot.
13F holdings are disclosed ~45 days after quarter-end, and they never reveal when within the quarter a fund actually bought. So any 13F-based summary is structurally late and blurred — this applies to every fund, including this one.
We backtested copying it anyway. Buying this fund's new positions the day each filing went public, over 29 quarters, returned -0.2% per quarter — versus +2.8% per quarter from simply owning every 13F stock. It beat that baseline in only 34.5% of quarters (excess t = -1.37, not statistically significant). Its filings tell you what it bought — not what you should buy.
Quarterly compounding, invested quarters only · entry 47 days after quarter-end (when 13F data becomes public)
Top 20 holdings of 88 · 2026 Q1
| Ticker | Value | Weight | QoQ |
|---|---|---|---|
| MDGL | $1.0B | | HOLD |
| INSM | $792M | | HOLD |
| PTGX | $533M | | HOLD |
| PTCT | $528M | | HOLD |
| ARGX | $518M | | ADD |
| CGON | $473M | | ADD |
| CELC | $347M | | ADD |
| TNGX | $278M | | ADD |
| ERAS | $261M | | ADD |
| NTRA | $250M | | TRIM |
| RDNT | $239M | | ADD |
| TARS | $235M | | HOLD |
| APGE | $234M | | ADD |
| SYRE | $210M | | HOLD |
| COGT | $210M | | TRIM |
| IRTC | $197M | | ADD |
| STOK | $183M | | HOLD |
| CYTK | $179M | | HOLD |
| ACAD | $159M | | HOLD |
| ESTA | $151M | | ADD |
QoQ vs previous quarter's share count · NEW = new position · ADD/TRIM = ±2% shares · HOLD = unchanged.
New positions in 2026 Q1
Method & Limitations
Method: a "new position" = held this quarter, absent last quarter (options excluded; stocks with <50 prior holders excluded to filter spin-off artifacts). Entry 47 days after quarter-end — the first day the public could act on the filing. Benchmark = equal-weighted universe of all 13F-held stocks. Limitations: quarterly snapshots can't see intra-quarter trades; survivorship bias — funds that shut down are absent, which flatters the sample. Statistics, not advice.