Builders FirstSource, Inc.
MX ˙ BMV ˙ US12008R1077
SecurityMX:BLDR / Builders FirstSource, Inc.
InstitutionWalleye Trading LLC
Latest Disclosed Ownership7,537 shares
Latest Disclosed Value $ 620,521
Walleye Trading LLC ownership in BLDR / Builders FirstSource, Inc.

On May 8, 2026 - Walleye Trading LLC filed a 13F-HR form disclosing ownership of 7,537 shares of Builders FirstSource, Inc. (MX:BLDR) valued at $620,521 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 11,243 shares of Builders FirstSource, Inc.. This represents a change in shares of -32.96% during the quarter.

Walleye Trading LLC has a history of taking positions in derivatives of the underlying security (BLDR) in the form of stock options. The firm currently holds call options representing 34,500 of underlying shares valued at $2,840,385 USD and put options representing 13,200 of underlying shares valued at $1,086,756 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:BLDR / Builders FirstSource, Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-08 2026-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 7,537 -3,706 -32.96 621 -46.37 0.0010
2026-02-13 2025-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 11,243 -19,645 -63.60 1,157 -69.13 0.0016
2025-11-14 2025-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 30,888 25,774 503.99 3,745 528.36 0.0057
2025-08-13 2025-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 5,114 -1,681 -24.74 597 -29.72 0.0011
2025-05-14 2025-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 6,795 -33,399 -83.09 849 -85.24 0.0020
2025-02-13 2024-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 40,194 -11,850 -22.77 5,745 -43.07 0.0121
2024-11-14 2024-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 52,044 -1,560 -2.91 10,089 35.99 0.0212
2024-08-14 2024-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 53,604 -28,044 -34.35 7,419 -56.43 0.0176
2024-05-15 2024-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 81,648 -38,001 -31.76 17,028 -14.75 0.0362
2024-02-14 2023-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 119,649 88,557 284.82 19,974 416.12 0.0430
2023-11-21 2023-09-30 13F/A-1 BUILDERS FIRSTSOURCE COM 12008R107 31,092 1,032 3.43 3,871 -5.33 0.0101
2023-11-14 2023-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 31,092 1,032 3,871 0.0102
2023-08-14 2023-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 30,060 30,060 4,088 0.0123
2022-11-14 2022-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 0 -12,828 -100.00 0 -100.00
2022-08-08 2022-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 12,828 -17,551 -57.77 689 -64.86 0.0022
2022-05-16 2022-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 30,379 -6,040 -16.58 1,961 -37.17 0.0063
2022-02-14 2021-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 36,419 19,824 119.46 3,121 263.33 0.0103
2021-11-15 2021-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 16,595 -44,511 -72.84 859 -67.05 0.0031
2021-08-16 2021-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 61,106 53,227 675.56 2,607 614.25 0.0102
2021-05-17 2021-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 7,879 7,879 365 0.0016
2020-11-16 2020-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 0 -2,279 -100.00 0 -100.00
2020-08-14 2020-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 2,279 -27,379 -92.32 47 -87.05 0.0003
2020-05-15 2020-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 29,658 29,658 363 0.0028
2020-02-14 2019-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 0 -1,939 -100.00 0 -100.00
2019-11-14 2019-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 1,939 -4,577 -70.24 40 -63.64 0.0003
2019-08-14 2019-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 6,516 -15,121 -69.88 110 -61.94 0.0009
2019-05-15 2019-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 21,637 -47,733 -68.81 289 -61.82 0.0022
2019-02-14 2018-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 69,370 16,907 32.23 757 -1.69 0.0056
2018-11-14 2018-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 52,463 -13,336 -20.27 770 -35.99 0.0041
2018-08-14 2018-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 65,799 64,449 4,774.00 1,203 4,355.56 0.0065
2018-05-15 2018-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 1,350 -2,385 -63.86 27 -66.67 0.0002
2018-02-14 2017-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 3,735 3,735 81 0.0004
2017-11-14 2017-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 0 -1,726 -100.00 0 -100.00
2017-08-14 2017-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 1,726 1,726 26 0.0002
2016-11-14 2016-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 0 -400 -100.00 0 -100.00
2016-08-15 2016-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 400 400 0.00 5 0.0000
2016-05-16 2016-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 0 -19,300 -100.00 0 -100.00
2016-02-16 2015-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 19,300 -4,600 -19.25 214 -29.37 0.0021
2015-11-16 2015-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 23,900 23,900 303 0.0028
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-08 2026-03-31 13F BUILDERS FIRSTSOURCE COM Call 34,500 -20.69 2,840 -36.54 n/a n/a n/a
2026-02-13 2025-12-31 13F BUILDERS FIRSTSOURCE COM Call 43,500 61.71 4,476 37.23 n/a n/a n/a
2025-11-14 2025-09-30 13F BUILDERS FIRSTSOURCE COM Call 26,900 24.54 3,262 29.40 n/a n/a n/a
2025-08-13 2025-06-30 13F BUILDERS FIRSTSOURCE COM Call 21,600 38.46 2,521 29.30 n/a n/a n/a
2025-05-14 2025-03-31 13F BUILDERS FIRSTSOURCE COM Call 15,600 -34.73 1,949 -42.94 n/a n/a n/a
2025-02-13 2024-12-31 13F BUILDERS FIRSTSOURCE COM Call 23,900 171.59 3,416 100.35 n/a n/a n/a
2024-11-14 2024-09-30 13F BUILDERS FIRSTSOURCE COM Call 8,800 91.30 1,706 168.08 n/a n/a n/a
2024-08-14 2024-06-30 13F BUILDERS FIRSTSOURCE COM Call 4,600 -29.23 637 -53.06 n/a n/a n/a
2024-05-15 2024-03-31 13F BUILDERS FIRSTSOURCE COM Call 6,500 -60.37 1,356 -50.49 n/a n/a n/a
2024-02-14 2023-12-31 13F BUILDERS FIRSTSOURCE COM Call 16,400 74.47 2,738 133.93 n/a n/a n/a
2023-11-21 2023-09-30 13F/A BUILDERS FIRSTSOURCE COM Call 9,400 -81.20 1,170 -82.79 n/a n/a n/a
2023-11-14 2023-09-30 13F BUILDERS FIRSTSOURCE COM Call 9,400 1,170 n/a n/a n/a
2023-08-14 2023-06-30 13F BUILDERS FIRSTSOURCE COM Call 50,000 -27.54 6,800 11.02 n/a n/a n/a
2023-05-15 2023-03-31 13F BUILDERS FIRSTSOURCE COM Call 69,000 49.35 6,126 104.37 n/a n/a n/a
2023-02-14 2022-12-31 13F BUILDERS FIRSTSOURCE COM Call 46,200 550.70 2,997 616.99 n/a n/a n/a
2022-11-14 2022-09-30 13F BUILDERS FIRSTSOURCE COM Call 7,100 -53.29 418 -48.77 n/a n/a n/a
2022-08-08 2022-06-30 13F BUILDERS FIRSTSOURCE COM Call 15,200 -46.10 816 -55.16 n/a n/a n/a
2022-05-16 2022-03-31 13F BUILDERS FIRSTSOURCE COM Call 28,200 70.91 1,820 28.71 n/a n/a n/a
2022-02-14 2021-12-31 13F BUILDERS FIRSTSOURCE COM Call 16,500 -28.57 1,414 18.33 n/a n/a n/a
2021-11-15 2021-09-30 13F BUILDERS FIRSTSOURCE COM Call 23,100 23,000.00 1,195 29,775.00 n/a n/a n/a
2021-08-16 2021-06-30 13F BUILDERS FIRSTSOURCE COM Call 100 -99.09 4 -99.22 n/a n/a n/a
2021-05-17 2021-03-31 13F BUILDERS FIRSTSOURCE COM Call 11,000 -70.59 510 -66.58 n/a n/a n/a
2021-02-16 2020-12-31 13F BUILDERS FIRSTSOURCE COM Call 37,400 -59.08 1,526 -48.81 n/a n/a n/a
2020-11-16 2020-09-30 13F BUILDERS FIRSTSOURCE COM Call 91,400 383.60 2,981 662.40 n/a n/a n/a
2020-08-14 2020-06-30 13F BUILDERS FIRSTSOURCE COM Call 18,900 -74.87 391 -57.50 n/a n/a n/a
2020-05-15 2020-03-31 13F BUILDERS FIRSTSOURCE COM Call 75,200 268.63 920 77.61 n/a n/a n/a
2020-02-14 2019-12-31 13F BUILDERS FIRSTSOURCE COM Call 20,400 106.06 518 153.92 n/a n/a n/a
2019-11-14 2019-09-30 13F BUILDERS FIRSTSOURCE COM Call 9,900 661.54 204 827.27 n/a n/a n/a
2019-08-14 2019-06-30 13F BUILDERS FIRSTSOURCE COM Call 1,300 30.00 22 69.23 n/a n/a n/a
2019-05-15 2019-03-31 13F BUILDERS FIRSTSOURCE COM Call 1,000 -98.36 13 -98.04 n/a n/a n/a
2019-02-14 2018-12-31 13F BUILDERS FIRSTSOURCE COM Call 60,800 2.36 663 -23.97 n/a n/a n/a
2018-11-14 2018-09-30 13F BUILDERS FIRSTSOURCE COM Call 59,400 736.62 872 570.77 n/a n/a n/a
2018-08-14 2018-06-30 13F BUILDERS FIRSTSOURCE COM Call 7,100 255.00 130 225.00 n/a n/a n/a
2018-05-15 2018-03-31 13F BUILDERS FIRSTSOURCE COM Call 2,000 -90.05 40 -90.87 n/a n/a n/a
2018-02-14 2017-12-31 13F BUILDERS FIRSTSOURCE COM Call 20,100 -36.79 438 -23.43 n/a n/a n/a
2017-11-14 2017-09-30 13F BUILDERS FIRSTSOURCE COM Call 31,800 221.21 572 276.32 n/a n/a n/a
2017-08-14 2017-06-30 13F BUILDERS FIRSTSOURCE COM Call 9,900 -92.80 152 -92.58 n/a n/a n/a
2017-05-15 2017-03-31 13F BUILDERS FIRSTSOURCE COM Call 137,500 2,049 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-08 2026-03-31 13F BUILDERS FIRSTSOURCE COM Put 13,200 -69.30 1,087 -75.45 n/a n/a n/a
2026-02-13 2025-12-31 13F BUILDERS FIRSTSOURCE COM Put 43,000 -21.39 4,424 -33.29 n/a n/a n/a
2025-11-14 2025-09-30 13F BUILDERS FIRSTSOURCE COM Put 54,700 86.69 6,632 93.97 n/a n/a n/a
2025-08-13 2025-06-30 13F BUILDERS FIRSTSOURCE COM Put 29,300 121.97 3,419 107.34 n/a n/a n/a
2025-05-14 2025-03-31 13F BUILDERS FIRSTSOURCE COM Put 13,200 -62.07 1,649 -66.84 n/a n/a n/a
2025-02-13 2024-12-31 13F BUILDERS FIRSTSOURCE COM Put 34,800 40.32 4,974 3.45 n/a n/a n/a
2024-11-14 2024-09-30 13F BUILDERS FIRSTSOURCE COM Put 24,800 2.90 4,808 44.14 n/a n/a n/a
2024-08-14 2024-06-30 13F BUILDERS FIRSTSOURCE COM Put 24,100 -42.21 3,336 -61.65 n/a n/a n/a
2024-05-15 2024-03-31 13F BUILDERS FIRSTSOURCE COM Put 41,700 -1.42 8,697 23.16 n/a n/a n/a
2024-02-14 2023-12-31 13F BUILDERS FIRSTSOURCE COM Put 42,300 104.35 7,062 174.11 n/a n/a n/a
2023-11-21 2023-09-30 13F/A BUILDERS FIRSTSOURCE COM Put 20,700 -13.03 2,577 -20.40 n/a n/a n/a
2023-11-14 2023-09-30 13F BUILDERS FIRSTSOURCE COM Put 20,700 2,577 n/a n/a n/a
2023-08-14 2023-06-30 13F BUILDERS FIRSTSOURCE COM Put 23,800 417.39 3,237 693.14 n/a n/a n/a
2023-05-15 2023-03-31 13F BUILDERS FIRSTSOURCE COM Put 4,600 -79.82 408 -72.41 n/a n/a n/a
2023-02-14 2022-12-31 13F BUILDERS FIRSTSOURCE COM Put 22,800 -83.67 1,479 -82.02 n/a n/a n/a
2022-11-14 2022-09-30 13F BUILDERS FIRSTSOURCE COM Put 139,600 8.64 8,225 19.20 n/a n/a n/a
2022-08-08 2022-06-30 13F BUILDERS FIRSTSOURCE COM Put 128,500 211.89 6,900 159.50 n/a n/a n/a
2022-05-16 2022-03-31 13F BUILDERS FIRSTSOURCE COM Put 41,200 110.20 2,659 58.27 n/a n/a n/a
2022-02-14 2021-12-31 13F BUILDERS FIRSTSOURCE COM Put 19,600 -19.01 1,680 34.19 n/a n/a n/a
2021-11-15 2021-09-30 13F BUILDERS FIRSTSOURCE COM Put 24,200 79.26 1,252 117.36 n/a n/a n/a
2021-08-16 2021-06-30 13F BUILDERS FIRSTSOURCE COM Put 13,500 -6.90 576 -14.29 n/a n/a n/a
2021-05-17 2021-03-31 13F BUILDERS FIRSTSOURCE COM Put 14,500 -66.51 672 -61.97 n/a n/a n/a
2021-02-16 2020-12-31 13F BUILDERS FIRSTSOURCE COM Put 43,300 -6.07 1,767 17.49 n/a n/a n/a
2020-11-16 2020-09-30 13F BUILDERS FIRSTSOURCE COM Put 46,100 262.99 1,504 471.86 n/a n/a n/a
2020-08-14 2020-06-30 13F BUILDERS FIRSTSOURCE COM Put 12,700 -72.63 263 -53.62 n/a n/a n/a
2020-05-15 2020-03-31 13F BUILDERS FIRSTSOURCE COM Put 46,400 7.91 567 -48.12 n/a n/a n/a
2020-02-14 2019-12-31 13F BUILDERS FIRSTSOURCE COM Put 43,000 325.74 1,093 425.48 n/a n/a n/a
2019-11-14 2019-09-30 13F BUILDERS FIRSTSOURCE COM Put 10,100 140.48 208 192.96 n/a n/a n/a
2019-08-14 2019-06-30 13F BUILDERS FIRSTSOURCE COM Put 4,200 71 n/a n/a n/a
2019-05-15 2019-03-31 13F BUILDERS FIRSTSOURCE COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-02-14 2018-12-31 13F BUILDERS FIRSTSOURCE COM Put 66,500 -8.28 726 -31.77 n/a n/a n/a
2018-11-14 2018-09-30 13F BUILDERS FIRSTSOURCE COM Put 72,500 935.71 1,064 731.25 n/a n/a n/a
2018-08-14 2018-06-30 13F BUILDERS FIRSTSOURCE COM Put 7,000 -43.55 128 -47.97 n/a n/a n/a
2018-05-15 2018-03-31 13F BUILDERS FIRSTSOURCE COM Put 12,400 181.82 246 156.25 n/a n/a n/a
2018-02-14 2017-12-31 13F BUILDERS FIRSTSOURCE COM Put 4,400 -12.00 96 6.67 n/a n/a n/a
2017-11-14 2017-09-30 13F BUILDERS FIRSTSOURCE COM Put 5,000 -45.65 90 -36.17 n/a n/a n/a
2017-08-14 2017-06-30 13F BUILDERS FIRSTSOURCE COM Put 9,200 -66.30 141 -65.36 n/a n/a n/a
2017-05-15 2017-03-31 13F BUILDERS FIRSTSOURCE COM Put 27,300 407 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.