Xilio Therapeutics, Inc. (XLO) Ownership
XLO ownership summary
as of October 18, 2026- Institutions
- 49.4% of shares outstanding
- Insiders
- 25.98% of shares outstanding
- Shares outstanding
- 6.6M
- Float
- 3.4M shares available to trade
- Short interest
- 6.96% 410K shares short
- Days to cover
- 38.99 short interest down 0.7% vs prior month
- Institutions 49.44%
- Insiders 25.98%
- Other investors 24.58%
XLO top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Bain Capital Life Sciences Investors, LLC | 10.09% | 664K | $5.7M | — | June 30, 2026 |
| 2 | Orbimed Advisors LLC | 9.00% | 592K | $5.1M | +592,300 (0.0%) | June 30, 2026 |
| 3 | Frazier Life Sciences Management, L.P. | 6.42% | 423K | $3.6M | — | June 30, 2026 |
| 4 | Stonepine Capital Management Llc | 3.43% | 226K | $1.9M | +161,832 (+252.2%) | June 30, 2026 |
| 5 | Vanguard Capital Management, LLC | 2.71% | 179K | $1.5M | +54,857 (+44.4%) | June 30, 2026 |
| 6 | Sio Capital Management, LLC | 2.32% | 152K | $1.3M | — | June 30, 2026 |
| 7 | Adage Capital Partners Gp LLC | 1.70% | 112K | $953,676 | +111,541 (0.0%) | June 30, 2026 |
| 8 | Merck & Co Inc | 1.61% | 106K | $906,146 | — | June 30, 2026 |
| 9 | Renaissance Technologies Corp | 0.97% | 64K | $548,508 | +14,587 (+29.4%) | June 30, 2026 |
| 10 | Morgan Stanley - Brokerage Accounts | 0.87% | 57K | $486,957 | −539 (−0.9%) | June 30, 2026 |
| 11 | AJU IB Investment Co Ltd | 0.72% | 48K | $407,792 | −620,047 (−92.9%) | March 31, 2026 |
| 12 | Geode Capital Management, LLC | 0.59% | 39K | $333,920 | +1,858 (+5.0%) | June 30, 2026 |
| 13 | Citadel Advisors Llc | 0.39% | 26K | $221,873 | +25,950 (0.0%) | June 30, 2026 |
| 14 | Vanguard Fiduciary Trust Co | 0.34% | 23K | $193,179 | −5,881 (−20.7%) | June 30, 2026 |
| 15 | Bridgeway Capital Management, LLC | 0.27% | 18K | $150,001 | +17,544 (0.0%) | June 30, 2026 |
| 16 | Two Sigma Investments LLC | 0.22% | 15K | $124,351 | +14,544 (0.0%) | June 30, 2026 |
| 17 | Velan Capital Investment Management LP | 0.22% | 14K | $122,137 | — | June 30, 2026 |
| 18 | GSA Capital Partners LLP | 0.21% | 14K | $116,195 | −3,356 (−19.8%) | June 30, 2026 |
| 19 | State Street Corp | 0.20% | 13K | $113,809 | — | June 30, 2026 |
| 20 | Springbok Capital Management, LLC | 0.18% | 12K | $99,180 | +11,600 (0.0%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 10 holders added 1.0M shares and 4 cut 630K.
XLO top mutual fund and ETF holders
15 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 2.16% | 142K | $1.2M | — | August 31, 2026 |
| 2 | Fidelity Extended Market Index | 0.29% | 19K | $165,511 | −104 (−0.5%) | August 31, 2026 |
| 3 | Bridgeway Ultra-Small Company | 0.27% | 18K | $150,001 | +17,544 (0.0%) | June 30, 2026 |
| 4 | Abante Quant Value FI | 0.24% | 16K | $133,619 | — | August 31, 2026 |
| 5 | iShares Micro-Cap ETF | 0.16% | 10K | $88,664 | −72 (−0.7%) | September 30, 2026 |
| 6 | Fidelity Series Total Market Index | 0.09% | 5,861 | $50,112 | — | August 31, 2026 |
| 7 | Fidelity Nasdaq Composite Index | 0.08% | 5,037 | $43,066 | — | August 31, 2026 |
| 8 | Fidelity Total Market Index | 0.07% | 4,514 | $38,595 | — | August 31, 2026 |
| 9 | DFA US Core Equity Class F | 0.02% | 1,545 | $13,210 | +1,545 (0.0%) | July 31, 2026 |
| 10 | DFA US Vector Equity I | 0.02% | 1,507 | $12,885 | — | August 31, 2026 |
| 11 | Dimensional US Core Equity 1 ETF | 0.02% | 1,116 | $9,542 | — | September 24, 2026 |
| 12 | 1290 VT Micro Cap K | 0.01% | 538 | $4,600 | — | August 31, 2026 |
| 13 | Vanguard Balanced Index Inv | 0.01% | 471 | $4,027 | — | August 31, 2026 |
| 14 | Dimensional US Core Equity 2 ETF | <0.01% | 254 | $2,172 | — | September 30, 2026 |
| 15 | Guggenheim Active Allocation Fund | <0.01% | 6 | $51 | +3 (+100.0%) | May 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
XLO insider transactions
latest 3| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2025-06-17 | James Samuel Shannon | Buy | $9.66 | 1,785 | $17,243 |
| 2025-06-16 | James Samuel Shannon | Buy | $9.66 | 3,214 | $31,047 |
| 2025-06-16 | Rene Russo | Buy | $9.52 | 2,592 | $24,676 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
XLO shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns XLO
Institutional investors own 49.4% of Xilio Therapeutics's shares and insiders 25.98%. The largest holder is Bain Capital Life Sciences Investors, LLC with 10.09% of the shares (664K), as of June 30, 2026. Among the top 20 institutions, 10 added shares and 4 reduced their stake in the latest filings. Short interest is 6.96% of the float, or 38.99 days of average trading volume. The share count rose 27,074.4% since 2020.
Related: XLO analyst forecast, XLO key metrics. See the XLO stock overview for the latest quote and news.
XLO ownership FAQ
Who owns the most Xilio Therapeutics stock?
The largest shareholders of Xilio Therapeutics are Bain Capital Life Sciences Investors, LLC (10.09%), Orbimed Advisors LLC (9.00%), Frazier Life Sciences Management, L.P. (6.42%), Stonepine Capital Management Llc (3.43%), Vanguard Capital Management, LLC (2.71%).
What percentage of Xilio Therapeutics is owned by institutions?
Institutions hold 49.4% of Xilio Therapeutics's shares outstanding; insiders hold 25.98%.
Which funds own Xilio Therapeutics?
The largest fund holders of Xilio Therapeutics are Vanguard MStar Total Stk Mkt Idx Invest (2.16%), Fidelity Extended Market Index (0.29%), Bridgeway Ultra-Small Company (0.27%), Abante Quant Value FI (0.24%), iShares Micro-Cap ETF (0.16%).
What is Xilio Therapeutics's short interest?
410K shares of Xilio Therapeutics were sold short, 6.96% of the float; at the average daily volume it would take 38.99 days to cover.
Are insiders buying or selling Xilio Therapeutics?
Of the latest 3 reported insider transactions in Xilio Therapeutics (since June 16, 2025), 3 were purchases and 0 were sales.
How many shares of Xilio Therapeutics are outstanding?
Xilio Therapeutics has 6.6M shares outstanding, of which 3.4M are in the public float.