William Blair & Company
KOS icon

William Blair & Company’s Kosmos Energy KOS Stock Holding History

William Blair & Company’s Portfolio KOS Stock Details KOS Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$278K Buy
100,069
+69
+0.1% +$130 ﹤0.01% 1364
2025
Q4 		$90.7K Hold
100,000
– – ﹤0.01% 1577
2025
Q3 		$166K Hold
100,000
– – ﹤0.01% 1495
2025
Q2 		$172K Buy
100,000
+50,000
+100% +$90.5K ﹤0.01% 1441
2025
Q1 		$114K Buy
+50,000
New +$148K ﹤0.01% 1479
2024
Q4 		– Sell
-69,662
Closed -$281K – 1854
2024
Q3 		$281K Buy
69,662
+5,223
+8% +$25.4K ﹤0.01% 1312
2024
Q2 		$357K Buy
64,439
+7,170
+13% +$41.8K ﹤0.01% 1206
2024
Q1 		$341K Hold
57,269
– – ﹤0.01% 1208
2023
Q4 		$384K Hold
57,269
– – ﹤0.01% 1149
2023
Q3 		$468K Buy
57,269
+12,121
+27% +$85.9K ﹤0.01% 1075
2023
Q2 		$270K Sell
45,148
-12,003
-21% -$78.2K ﹤0.01% 1290
2023
Q1 		$425K Buy
+57,151
New +$419K ﹤0.01% 1105

Other funds holding KOS

BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
EPIM
Equinox Partners Investment Management Stamford, Connecticut $245M AUM 225.58% 1-Year Est. Return
D.E. Shaw & Co
D.E. Shaw & Co New York $166B AUM 43.98% 1-Year Est. Return
Hotchkis & Wiley Capital Management
Hotchkis & Wiley Capital Management Los Angeles, California $32.4B AUM 17.21% 1-Year Est. Return
Two Sigma Investments
Two Sigma Investments New York $124B AUM 33.93% 1-Year Est. Return
Grantham, Mayo, Van Otterloo & Co (GMO)
Grantham, Mayo, Van Otterloo & Co (GMO) Boston, Massachusetts $39.1B AUM 28.69% 1-Year Est. Return
Charles Schwab
Charles Schwab San Francisco, California $654B AUM 26.35% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
Millennium Management
Millennium Management New York $240B AUM 35.51% 1-Year Est. Return

William Blair & Company's KOS Position: Q1 2026 in Review

William Blair & Company increased its Kosmos Energy (KOS) stake by 0.07% in Q1 2026, buying an estimated $130 and bringing the position to 100,069 shares worth $278K. The position accounts for ﹤0.01% of the portfolio, ranked #1364.

William Blair & Company first reported a position in KOS in Q1 2023 and has held it in 12 quarters since. The position peaked at $468K in Q3 2023. 262 funds tracked by Wall St. Rank hold KOS as of Q1 2026.

  • William Blair & Company held 100,069 shares of Kosmos Energy worth $278K as of Q1 2026.
  • William Blair & Company bought 69 Kosmos Energy shares in Q1 2026, an estimated $130.
  • Kosmos Energy made up ﹤0.01% of William Blair & Company's portfolio in Q1 2026, its #1364 holding.
  • William Blair & Company first reported a position in Kosmos Energy in Q1 2023 and has held it in 12 quarters since.
  • William Blair & Company's Kosmos Energy position peaked at $468K in Q3 2023.
  • 262 funds tracked by Wall St. Rank held Kosmos Energy as of Q1 2026.

Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.