James B. Tananbaum Portfolio
Invests via Foresite Capital Management VI LLC | Managed by James B. Tananbaum
Invests via Foresite Capital Management VI LLC
Managed by James B. Tananbaum
Automatically Tracked
James B. Tananbaum Profile
Veteran life-sciences investor and founder-CEO known for building a crossover bio-focused investment platform that deploys patient capital across public and private companies.
James B. Tananbaum leads RA Capital, directing concentrated equity and venture investments in therapeutics, diagnostics and platform biotech, and serves on multiple corporate boards while positioning the firm between VC and long-only strategies to finance translational R&D and late-stage clinical value creation.
Veteran life-sciences investor and founder-CEO known for building a crossover bio-focused investment platform that deploys patient capital across public and private companies.
James B. Tananbaum leads RA Capital, directing concentrated equity and venture investments in therapeutics, diagnostics and platform biotech, and serves on multiple corporate boards while positioning the firm between VC and long-only strategies to finance translational R&D and late-stage clinical value creation.
Investment Philosophy & Strategy
Deploys patient, concentrated capital across public and private life-science companies, prioritizing therapeutics, diagnostics and platform biotech. Blends venture and crossover approaches to underwrite translational R&D and late-stage clinical value creation, favoring investments where scientific validation, regulatory path and clear clinical catalysts align. Time horizon is multi-stage and long, with active board engagement to derisk development and shape value inflection. Capital allocation emphasizes concentrated, conviction positions complemented by stage diversification and exit-ready public stakes. Risk discipline centers on technical due diligence, milestone-driven financing and portfolio sizing around asymmetric risk/reward.
Deploys patient, concentrated capital across public and private life-science companies, prioritizing therapeutics, diagnostics and platform biotech. Blends venture and crossover approaches to underwrite translational R&D and late-stage clinical value creation, favoring investments where scientific validation, regulatory path and clear clinical catalysts align. Time horizon is multi-stage and long, with active board engagement to derisk development and shape value inflection. Capital allocation emphasizes concentrated, conviction positions complemented by stage diversification and exit-ready public stakes. Risk discipline centers on technical due diligence, milestone-driven financing and portfolio sizing around asymmetric risk/reward.
Disclaimer: This Portfolio is derived from and computed based on publicly available data from SEC filings.
Gain and growth charts are calculated per selected timeframe:
79.39%
Gain +1.17%
Monthly
2.76%
Yearly
38.63%
Drawdown
40.49%
$474.26M
Equity
Holdings
$474.26M
Investment
$400.95M
$123.02M
Profit +$4.28M
Realized
$49.71M
Unrealized
$73.31M
Dividends
$0
Goals
Avg. 0% completed goals
Yearly
Gain > 5% 2026
Yearly
Gain < 20% 2026
Today
Compared To Yesterday
Gain
1.17%
Profit
$4.28M
Win %
40%
This Week
Compared To Last Week
Gain
-4.93%
Profit
-$24.59M
Win %
40%
This Month
Compared to last month
Gain
-11.41%
Profit
-$61.08M
Win %
40%
This Year
Compared to last year
Gain
-21.82%
Profit
-$144.32M
Win %
47%
ALMS Alumis Inc.
+4.62%
+$1.19M 
KLRA Kailera Therapeutics, Inc.
+4.1%
+$16,500 
SPTX Seaport Therapeutics, Inc.
+3.18%
+$943,146.13 
JBIO Jade Biosciences Inc.
+2.98%
+$354,666.8 
VSTM Verastem Inc.
+2.66%
+$645,059.35 
IRON Disc Medicine Inc.
+2.52%
+$1,362.85 
AGIO Agios Pharmaceuticals Inc.
+2.49%
+$604,450 
AVBP Arrivent Biopharma Inc.
+1.85%
+$90,402.3 
CLDX Celldex Therapeutics Inc.
+1.8%
+$439,856.5 
DNLI Denali Therapeutics Inc.
+1.74%
+$432,999.01 
CRVS Corvus Pharmaceuticals Inc.
+1.49%
+$256,372.62 
AURA Aura Biosciences Inc.
+1.46%
+$120,000.06 
GHRS GH Research plc
+1.02%
+$178,693.67 
KYMR Kymera Therapeutics Inc.
+0.9%
+$140,478.72 
NERV Minerva Neurosciences Inc.
+0.43%
+$19,855.84 
RACC Research Alliance Corporation III
+0.39%
+$12,000 
ATAI AtaiBeckley Inc.
0%
$0 
CRNX Crinetics Pharmaceuticals Inc.
0%
$0 
Events
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Dividends
Dividend Analysis
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No Data
| Trades 67 | Longs Won 27/67 40% | Profit Factor 2.45 |
| Profitability | Shorts Won 0/0 0% | Standard Deviation $11.3M |
| Average Win $7.69M | Best Trade (Oct 14) $74.91M | Sharpe Ratio -17.25 |
| Average Loss -$2.12M | Worst Trade (Sep 29) -$7.95M | Z-Score -2.49 (100%) |
| Commissions $0 | Avg. Trade Length 7m 3w 4d | Expectancy $1.84M |
| Loss Size | 100% | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
| Probability of Loss | <0.01% | <0.01% | <0.01% | <0.01% | <0.01% | 0.01% | 0.1% | 0.82% | 4.95% | 24.2% |
| Consecutive Losing Trades | 224 | 202 | 179 | 157 | 135 | 112 | 90 | 67 | 45 | 22 |
Hover over the desired column for a detailed explanation.
Returns
Overall, Monthly| Symbol | Quantity | Cost | Value | Comm. | Profit ($) | Gain (%) | Change |
|---|---|---|---|---|---|---|---|
| AGIO Agios Pharmaceuticals Inc. | 785,000 | $23.94M | $24.92M | - | $976,800 | 4.08% | +2.486% |
| ALMS Alumis Inc. | 4.25M | $33.17M | $26.93M | - | -$6.24M | -18.81% | +4.62% |
| ATAI AtaiBeckley Inc. | 2.75M | $9.73M | $9.73M | - | - | - | 0.0 |
| AURA Aura Biosciences Inc. | 1.33M | $9.47M | $8.35M | - | -$1.12M | -11.83% | +1.459% |
| AVBP Arrivent Biopharma Inc. | 301,341 | $10.47M | $4.97M | - | -$5.5M | -52.5% | +1.852% |
 BEAM Beam Therapeutics Inc. | 330,000 | $11.33M | $7.78M | - | -$3.55M | -31.34% | -0.359% |
 CGON CG Oncology, Inc. | 2.37M | $74.23M | $146.44M | - | $72.21M | 97.27% | -0.065% |
| CLDX Celldex Therapeutics Inc. | 879,713 | $31M | $24.93M | - | -$6.07M | -19.58% | +1.796% |
| CRNX Crinetics Pharmaceuticals Inc. | 212,010 | $7.7M | $18.01M | - | $10.31M | 133.89% | 0.0 |
| CRVS Corvus Pharmaceuticals Inc. | 1.83M | $13.77M | $17.43M | - | $3.66M | 26.6% | +1.493% |
| DNLI Denali Therapeutics Inc. | 1.4M | $23.36M | $25.39M | - | $2.04M | 8.72% | +1.735% |
| GHRS GH Research plc | 940,493 | $20.27M | $17.63M | - | -$2.64M | -13.02% | +1.024% |
 HNGE Hinge Health Inc. | 220,400 | $10.28M | $22.81M | - | $12.53M | 121.92% | -1.429% |
| IRON Disc Medicine Inc. | 970 | $70,946 | $55,430.65 | - | -$15,515.35 | -21.87% | +2.521% |
| JBIO Jade Biosciences Inc. | 886,667 | $17.09M | $12.27M | - | -$4.82M | -28.18% | +2.976% |
| KLRA Kailera Therapeutics, Inc. | 37,500 | $826,125 | $419,250 | - | -$406,875 | -49.25% | +4.097% |
| KYMR Kymera Therapeutics Inc. | 146,332 | $5.89M | $15.77M | - | $9.89M | 167.93% | +0.899% |
| NERV Minerva Neurosciences Inc. | 1.99M | $11.96M | $4.69M | - | -$7.28M | -60.83% | +0.426% |
 PBLS Parabilis Medicines, Inc. | 999,044 | $27.34M | $25.23M | - | -$2.12M | -7.75% | -2.472% |
| RACC Research Alliance Corporation III | 300,000 | $3.21M | $3.06M | - | -$153,000 | -4.77% | +0.394% |
No Data
Option values are updated at end of day.
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Option values are updated at end of day.
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FAQ
Which stocks have generated the highest profits for James B. Tananbaum?
The largest contributions to the portfolio's profits come from the following stocks: Rapt Therapeutics, Inc - $35.92M, Centessa Pharmaceuticals plc American Depositary Receipt - $30.46M, Akero Therapeutics, Inc - $7.88M, Xenon Pharmaceuticals Inc - $1.42M, and Ideaya Biosciences Inc - $894,257.28. These positions have been the main drivers of growth and have significantly impacted the investor's overall performance.
Which stocks have generated the largest losses for this investor?
The largest losses in the portfolio are associated with the following stocks: Edgewise Therapeutics, Inc - $7.95M, Bicara Therapeutics Inc - $7.72M, Allogene Therapeutics Inc - $3.45M, Cullinan Therapeutics, Inc - $2.95M, and Structure Therapeutics Inc - $2.68M. These positions have had the most negative impact on overall performance and highlight the weaker areas of the portfolio.
How stable are James B. Tananbaum's monthly returns?
James B. Tananbaum's monthly returns look highly volatile. The portfolio shows large month-to-month swings, and the broader risk profile suggests that performance can change sharply over short periods. This kind of pattern may suit users who are comfortable with significant fluctuations, but it is less likely to appeal to those who prefer steadier and more predictable results.
Can James B. Tananbaum's strategy be considered aggressive or moderate?
James B. Tananbaum's strategy can be considered aggressive. The combination of high drawdowns, elevated volatility, and/or concentrated positions suggests a willingness to accept significant risk in pursuit of higher long-term returns. This approach is generally more suitable for users who are comfortable with large fluctuations in portfolio value.
Should beginners follow James B. Tananbaum's strategy?
James B. Tananbaum's strategy is unlikely to be suitable for beginners. The portfolio shows signs of high risk, significant volatility, or structural complexity, which can make it difficult to follow and potentially stressful for less experienced users. This type of approach is generally better suited to more advanced investors.
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