Boston Partners
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Boston Partners’s White Mountains Insurance WTM Stock Holding History

Boston Partners’s Portfolio WTM Stock Details WTM Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$126M Sell
57,459
-19,452
-25% -$41.6M 0.13% 196
2025
Q4 		$160M Sell
76,911
-7,534
-9% -$14.7M 0.17% 188
2025
Q3 		$143M Sell
84,445
-4,949
-6% -$8.83M 0.15% 190
2025
Q2 		$160M Buy
89,394
+4,158
+5% +$7.4M 0.18% 186
2025
Q1 		$163M Sell
85,236
-209
-0.2% -$393K 0.2% 173
2024
Q4 		$166M Buy
85,445
+348
+0.4% +$658K 0.2% 169
2024
Q3 		$145M Sell
85,097
-2,574
-3% -$4.49M 0.17% 186
2024
Q2 		$159M Sell
87,671
-2,923
-3% -$5.17M 0.2% 172
2024
Q1 		$162M Sell
90,594
-1,958
-2% -$3.28M 0.19% 176
2023
Q4 		$140M Sell
92,552
-21,947
-19% -$32.6M 0.19% 182
2023
Q3 		$171M Sell
114,499
-3,506
-3% -$5.38M 0.24% 140
2023
Q2 		$165M Sell
118,005
-7,532
-6% -$10.6M 0.22% 143
2023
Q1 		$174M Buy
125,537
+1,217
+1% +$1.75M 0.24% 138
2022
Q4 		$177M Sell
124,320
-3,692
-3% -$5M 0.24% 138
2022
Q3 		$168M Sell
128,012
-5,203
-4% -$6.73M 0.25% 132
2022
Q2 		$166M Sell
133,215
-2,193
-2% -$2.55M 0.23% 139
2022
Q1 		$154M Sell
135,408
-2,428
-2% -$2.54M 0.19% 166
2021
Q4 		$140M Sell
137,836
-5,996
-4% -$6.33M 0.17% 180
2021
Q3 		$154M Buy
143,832
+3,373
+2% +$3.77M 0.2% 167
2021
Q2 		$161M Buy
140,459
+3,264
+2% +$3.81M 0.21% 164
2021
Q1 		$154M Buy
137,195
+5,199
+4% +$5.81M 0.21% 163
2020
Q4 		$132M Sell
131,996
-85
-0.1% -$80K 0.21% 161
2020
Q3 		$103M Sell
132,081
-5,387
-4% -$4.66M 0.19% 161
2020
Q2 		$122M Sell
137,468
-6,943
-5% -$6.26M 0.22% 133
2020
Q1 		$131M Sell
144,411
-2,926
-2% -$3.03M 0.26% 115
2019
Q4 		$164M Sell
147,337
-10,402
-7% -$11.3M 0.22% 131
2019
Q3 		$170M Sell
157,739
-7,184
-4% -$7.66M 0.23% 123
2019
Q2 		$169M Sell
164,923
-2,329
-1% -$2.24M 0.22% 138
2019
Q1 		$155M Sell
167,252
-8,095
-5% -$7.33M 0.21% 143
2018
Q4 		$150M Buy
175,347
+12,696
+8% +$11.3M 0.22% 133
2018
Q3 		$152M Buy
162,651
+2,361
+1% +$2.19M 0.18% 149
2018
Q2 		$145M Buy
160,290
+1,959
+1% +$1.73M 0.17% 152
2018
Q1 		$130M Sell
158,331
-3,128
-2% -$2.58M 0.16% 168
2017
Q4 		$137M Buy
161,459
+31,537
+24% +$27.6M 0.16% 157
2017
Q3 		$111M Buy
129,922
+2,417
+2% +$2.08M 0.14% 177
2017
Q2 		$111M Sell
127,505
-453
-0.4% -$393K 0.14% 170
2017
Q1 		$113M Buy
127,958
+2,979
+2% +$2.67M 0.14% 176
2016
Q4 		$104M Sell
124,979
-194
-0.2% -$163K 0.14% 176
2016
Q3 		$104M Sell
125,173
-1,883
-1% -$1.55M 0.15% 169
2016
Q2 		$107M Sell
127,056
-3,881
-3% -$3.17M 0.15% 175
2016
Q1 		$105M Sell
130,937
-6,454
-5% -$4.83M 0.15% 173
2015
Q4 		$99.9M Sell
137,391
-1,050
-0.8% -$804K 0.14% 168
2015
Q3 		$103M Sell
138,441
-4,334
-3% -$3.12M 0.16% 159
2015
Q2 		$93.5M Buy
142,775
+1,538
+1% +$1.02M 0.13% 176
2015
Q1 		$96.7M Buy
141,237
+11,613
+9% +$7.66M 0.14% 171
2014
Q4 		$81.7M Sell
129,624
-3,980
-3% -$2.53M 0.12% 172
2014
Q3 		$84.2M Sell
133,604
-3,276
-2% -$2.04M 0.14% 161
2014
Q2 		$83.3M Sell
136,880
-7,204
-5% -$4.29M 0.14% 163
2014
Q1 		$86.4M Sell
144,084
-5,273
-4% -$3.08M 0.16% 155
2013
Q4 		$90.1M Sell
149,357
-8,607
-5% -$5.07M 0.18% 142
2013
Q3 		$89.7M Sell
157,964
-1,133
-0.7% -$658K 0.22% 129
2013
Q2 		$91.5M Buy
+159,097
New +$92.8M 0.25% 113

Other funds holding WTM

Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $481B AUM 30.42% 1-Year Est. Return
Neuberger Berman Group
Neuberger Berman Group New York $131B AUM 28.36% 1-Year Est. Return
RRAM
River Road Asset Management Louisville, Kentucky $8.99B AUM 12.83% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
CB
Cooke & Bieler Philadelphia, Pennsylvania $8.84B AUM 6.92% 1-Year Est. Return
Fuller & Thaler Asset Management
Fuller & Thaler Asset Management San Mateo, California $29.7B AUM 43.33% 1-Year Est. Return
FMI
Fiduciary Management Inc Milwaukee, Wisconsin $8.06B AUM 6.78% 1-Year Est. Return
WCM
Wallace Capital Management Dallas, Texas $871M AUM 13.69% 1-Year Est. Return

Boston Partners's WTM Position: Q1 2026 in Review

Boston Partners reduced its White Mountains Insurance (WTM) stake by 25% in Q1 2026, selling an estimated $41.6M and leaving 57,459 shares worth $126M. The position accounts for 0.13% of the portfolio, ranked #196.

Boston Partners first reported a position in WTM in Q2 2013 and has held it in 52 quarters since. The position peaked at $177M in Q4 2022. 367 funds tracked by Wall St. Rank hold WTM as of Q1 2026.

  • Boston Partners held 57,459 shares of White Mountains Insurance worth $126M as of Q1 2026.
  • Boston Partners sold 19,452 White Mountains Insurance shares in Q1 2026, an estimated $41.6M.
  • White Mountains Insurance made up 0.13% of Boston Partners's portfolio in Q1 2026, its #196 holding.
  • Boston Partners first reported a position in White Mountains Insurance in Q2 2013 and has held it in 52 quarters since.
  • Boston Partners's White Mountains Insurance position peaked at $177M in Q4 2022.
  • 367 funds tracked by Wall St. Rank held White Mountains Insurance as of Q1 2026.

Based on Boston Partners's 13F filing for Q1 2026, filed 11 May 2026.