Superstring Capital Management L.P. 13F annual report

Superstring Capital Management L.P. is an investment fund managing more than $151 billion ran by George Song. There are currently 37 companies in Mr. Song’s portfolio. The largest investments include Cytokinetics Inc and Nkarta, together worth $32.4 billion.

Limited to 30 biggest holdings

$151 billion Assets Under Management (AUM)

As of 8th May 2024, Superstring Capital Management L.P.’s top holding is 278,915 shares of Cytokinetics Inc currently worth over $19.6 billion and making up 12.9% of the portfolio value. Relative to the number of outstanding shares of Cytokinetics Inc, Superstring Capital Management L.P. owns more than approximately 0.1% of the company. In addition, the fund holds 1,189,193 shares of Nkarta worth $12.9 billion, whose value grew 221.8% in the past six months. The third-largest holding is 89bio Inc worth $11 billion and the next is BridgeBio Pharma Inc worth $10.9 billion, with 353,507 shares owned.

Currently, Superstring Capital Management L.P.'s portfolio is worth at least $151 billion. The total portfolio value may be much higher due to cash assets that are not publicly disclosed such as fixed income, real estate, or cash equivalents.

Careers at Superstring Capital Management L.P.

The Superstring Capital Management L.P. office and employees reside in New York, New York. According to the last 13-F report filed with the SEC, George Song serves as the COO/CFO at Superstring Capital Management L.P..

Recent trades

In the most recent 13F filing, Superstring Capital Management L.P. revealed that it had opened a new position in Cabaletta Bio Inc and bought 290,797 shares worth $4.96 billion. This means they effectively own approximately 0.1% of the company. Cabaletta Bio Inc makes up 4.0% of the fund's Health Care sector allocation and has decreased its share price by 2.2% in the past year.

The investment fund also strengthened its position in Cytokinetics Inc by buying 101,312 additional shares. This makes their stake in Cytokinetics Inc total 278,915 shares worth $19.6 billion. Cytokinetics Inc soared 52.4% in the past year.

On the other hand, there are companies that Superstring Capital Management L.P. is getting rid of from its portfolio. Superstring Capital Management L.P. closed its position in Immunogen on 15th May 2024. It sold the previously owned 598,072 shares for $17.7 billion. George Song also disclosed a decreased stake in 89bio Inc by approximately 0.1%. This leaves the value of the investment at $11 billion and 941,287 shares.

One of the smallest hedge funds

The two most similar investment funds to Superstring Capital Management L.P. are Baron and Potrero Capital Research. They manage $151 billion and $151 billion respectively.


George Song investment strategy

Superstring Capital Management L.P.’s portfolio is diversified across 2 sectors. Currently, their heaviest sector is Health Care — making up 82.3% of the total portfolio value. The fund focuses on investments in the United States as 62.2% of the portfolio companies are based in the United States.

The majority of the companies in the fund’s portfolio are small-cap stocks. Stocks with a size of more than $100 million in market cap make up 11% of the total holdings value. On the other hand, large-cap stocks make up only approximately 0.1% of the portfolio. The average market cap of the portfolio companies is close to $1.13 billion.

The complete list of Superstring Capital Management L.P. trades based on 13F SEC filings

These positions were updated on May 15th based on the fund’s latest 13F filing. Quickly find out what the most recently closed or increased positions are.

Security Shares Owned Value Allocation
Cytokinetics Inc
57.04%
278,915
$19,554,730,000 12.93%
Immunogen, Inc.
Closed
598,072
$17,732,835,000
Nkarta, Inc.
242.33%
1,189,193
$12,855,176,000 8.50%
89bio Inc
7.85%
941,287
$10,956,580,000 7.24%
BridgeBio Pharma Inc
71.33%
353,507
$10,930,436,000 7.23%
Savara Inc
153.62%
2,065,144
$10,284,417,000 6.80%
IDEAYA Biosciences, Inc.
13.62%
217,070
$9,525,031,000 6.30%
Protagonist Therapeutics Inc
Closed
379,143
$8,693,749,000
Immunovant Inc
Closed
203,592
$8,577,331,000
Fate Therapeutics Inc
8.57%
920,476
$6,756,294,000 4.47%
Day One Biopharmaceuticals I
7.89%
349,679
$5,776,697,000 3.82%
Roivant Sciences Ltd
62.81%
531,019
$5,596,940,000 3.70%
Ionis Pharmaceuticals Inc
36.24%
120,896
$5,240,842,000 3.47%
Marinus Pharmaceuticals Inc
22.30%
565,550
$5,112,572,000 3.38%
Cabaletta Bio Inc
Opened
290,797
$4,960,997,000 3.28%
UroGen Pharma Ltd
12.86%
288,267
$4,324,005,000 2.86%
Verona Pharma Plc
109.11%
259,383
$4,173,472,000 2.76%
Neurocrine Biosciences, Inc.
Closed
29,346
$3,866,629,000
Lantheus Holdings Inc
Closed
54,896
$3,403,552,000
Aerovate Therapeutics Inc
Opened
110,264
$3,260,506,000 2.16%
Apogee Therapeutics Inc
Opened
44,868
$2,981,479,000 1.97%
Axsome Therapeutics Inc
126.26%
36,607
$2,921,239,000 1.93%
Dyne Therapeutics, Inc.
Opened
99,822
$2,833,947,000 1.87%
Acelyrin Inc
Closed
356,924
$2,662,653,000
Praxis Precision Medicines I
Opened
40,119
$2,448,061,000 1.62%
Allogene Therapeutics Inc
134.68%
521,249
$2,329,983,000 1.54%
Keros Therapeutics, Inc.
54.68%
33,828
$2,239,413,000 1.48%
Pyxis Oncology Inc
Opened
493,759
$2,103,414,000 1.39%
Krystal Biotech Inc
Closed
16,086
$1,995,629,000
Quanterix Corp
Closed
71,760
$1,961,918,000
Ascendis Pharma A/S
Opened
12,754
$1,928,022,000 1.27%
Pepgen Inc
Opened
114,385
$1,681,460,000 1.11%
Tourmaline Bio Inc
Opened
69,972
$1,602,359,000 1.06%
Allakos Inc
Opened
1,233,739
$1,554,512,000 1.03%
CytomX Therapeutics Inc
Opened
679,403
$1,481,099,000 0.98%
Annexon Inc
Opened
155,728
$1,116,569,000 0.74%
Avidity Biosciences, Inc.
Opened
37,031
$945,031,000 0.62%
Lyra Therapeutics, Inc.
Opened
145,284
$903,667,000 0.60%
Inozyme Pharma, Inc.
9.04%
112,739
$863,581,000 0.57%
Immatics N.v
Closed
79,213
$834,113,000
Aurinia Pharmaceuticals Inc
Opened
98,691
$494,443,000 0.33%
Fusion Pharmaceuticals Inc.
Closed
45,801
$440,148,000
KalVista Pharmaceuticals Inc
Opened
32,025
$379,817,000 0.25%
Alpine Immune Sciences Inc
Opened
9,038
$358,267,000 0.24%
Spruce Biosciences, Inc.
270.52%
440,225
$345,973,000 0.23%
Ys Biopharma Co Ltd
No change
307,920
$215,544,000 0.14%
So-Young International Inc.
77.04%
182,742
$199,189,000 0.13%
No transactions found
Showing first 500 out of 47 holdings