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
Q3 		$254K Sell
100,000
-9,544
-9% -$24.8K ﹤0.01% 1457
2026
Q2 		$231K Buy
109,544
+9,475
+9% +$26.4K ﹤0.01% 1519
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

Phoenix Financial
Phoenix Financial Givatayim, Israel $14.8B AUM 42.86% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.92T AUM 36.1% 1-Year Est. Return
Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $551B AUM 33.95% 1-Year Est. Return
M&G plc
M&G plc London, United Kingdom $19.9B AUM 15.09% 1-Year Est. Return
Squarepoint
Squarepoint New York $90.8B AUM 26.98% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $765B AUM 28.39% 1-Year Est. Return
Russell Investments Group
Russell Investments Group London, United Kingdom $114B AUM 33.83% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.32T AUM 44.66% 1-Year Est. Return
Nuveen
Nuveen Charlotte, North Carolina $420B AUM 34.97% 1-Year Est. Return
Ballast Asset Management
Ballast Asset Management Dallas, Texas $230M AUM 34.36% 1-Year Est. Return

William Blair & Company's KOS Position: Q3 2026 in Review

William Blair & Company reduced its Kosmos Energy (KOS) stake by 8.7% in Q3 2026, selling an estimated $24.8K and leaving 100,000 shares worth $254K. The position accounts for ﹤0.01% of the portfolio, ranked #1457.

William Blair & Company first reported a position in KOS in Q1 2023 and has held it in 14 quarters since. The position peaked at $468K in Q3 2023. 120 funds tracked by Wall St. Rank hold KOS as of Q3 2026.

  • William Blair & Company held 100,000 shares of Kosmos Energy worth $254K as of Q3 2026.
  • William Blair & Company sold 9,544 Kosmos Energy shares in Q3 2026, an estimated $24.8K.
  • Kosmos Energy made up ﹤0.01% of William Blair & Company's portfolio in Q3 2026, its #1457 holding.
  • William Blair & Company first reported a position in Kosmos Energy in Q1 2023 and has held it in 14 quarters since.
  • William Blair & Company's Kosmos Energy position peaked at $468K in Q3 2023.
  • 120 funds tracked by Wall St. Rank held Kosmos Energy as of Q3 2026.

Based on William Blair & Company's 13F filing for Q3 2026, filed 10 Nov 2026.