Lam Research Corporation
US ˙ NasdaqGS ˙ US5128071082

SecurityLRCX / Lam Research Corporation
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership1,114,732 shares
Latest Disclosed Value $ 238,173,639
Citadel Advisors Llc ownership in LRCX / Lam Research Corporation

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 1,114,732 shares of Lam Research Corporation (US:LRCX) valued at $238,173,639 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 4,241,466 shares of Lam Research Corporation. This represents a change in shares of -73.72% during the quarter. The current value of the position is $338,075,921 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (LRCX) in the form of stock options. The firm currently holds call options representing 3,111,100 of underlying shares valued at $664,717,626 USD and put options representing 1,978,700 of underlying shares valued at $422,769,042 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.

LRCX / Lam Research Corporation 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)
2026-05-15 2026-03-31 13F LAM RESEARCH COM NEW 512807306 1,114,732 -3,126,734 -73.72 238,174 -67.20 0.0339
2026-02-17 2025-12-31 13F LAM RESEARCH COM NEW 512807306 4,241,466 1,195,246 39.24 726,054 78.00 0.1090
2025-11-14 2025-09-30 13F LAM RESEARCH COM NEW 512807306 3,046,220 -3,323,087 -52.17 407,889 -34.21 0.0621
2025-08-14 2025-06-30 13F LAM RESEARCH COM NEW 512807306 6,369,307 -283,721 -4.26 619,988 28.18 0.1076
2025-05-15 2025-03-31 13F LAM RESEARCH COM NEW 512807306 6,653,028 3,533,268 113.25 483,675 114.64 0.0917
2025-02-14 2024-12-31 13F LAM RESEARCH COM NEW 512807306 3,119,760 3,119,760 225,340 0.0390
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
(%)
2026-05-15 2026-03-31 13F LAM RESEARCH COM NEW Call 3,111,100 -26.85 664,718 -8.69 n/a n/a n/a
2026-02-17 2025-12-31 13F LAM RESEARCH COM NEW Call 4,252,900 51.67 728,011 93.89 n/a n/a n/a
2025-11-14 2025-09-30 13F LAM RESEARCH COM NEW Call 2,804,100 20.45 375,469 65.68 n/a n/a n/a
2025-08-14 2025-06-30 13F LAM RESEARCH COM NEW Call 2,328,100 -43.17 226,617 -23.91 n/a n/a n/a
2025-05-15 2025-03-31 13F LAM RESEARCH COM NEW Call 4,096,500 -14.10 297,816 -13.54 n/a n/a n/a
2025-02-14 2024-12-31 13F LAM RESEARCH COM NEW Call 4,768,900 344,458 n/a n/a n/a
2017-01-31 2016-09-30 13F/A LAM RESEARCH Cmn Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-01-31 2016-06-30 13F/A LAM RESEARCH Cmn Call 92,700 -2.32 7,792 -0.60 n/a n/a n/a
2016-08-12 2016-06-30 13F LAM RESEARCH Cmn Call 92,700 7,792 n/a n/a n/a
2017-01-31 2016-03-31 13F/A LAM RESEARCH Cmn Call 94,900 -17.33 7,839 -14.02 n/a n/a n/a
2016-05-13 2016-03-31 13F LAM RESEARCH Cmn Call 94,900 7,839 n/a n/a n/a
2017-01-31 2015-12-31 13F/A LAM RESEARCH Cmn Call 114,800 -50.07 9,117 -39.30 n/a n/a n/a
2016-02-12 2015-12-31 13F LAM RESEARCH Cmn Call 114,800 9,117 n/a n/a n/a
2015-11-16 2015-09-30 13F LAM RESEARCH Cmn Call 229,900 154.88 15,019 104.67 n/a n/a n/a
2015-08-14 2015-06-30 13F LAM RESEARCH Cmn Call 90,200 50.58 7,338 74.42 n/a n/a n/a
2015-05-15 2015-03-31 13F LAM RESEARCH Cmn Call 59,900 -45.00 4,207 -51.31 n/a n/a n/a
2015-02-17 2014-12-31 13F LAM RESEARCH Cmn Call 108,900 -16.42 8,640 -11.23 n/a n/a n/a
2014-11-14 2014-09-30 13F LAM RESEARCH Cmn Call 130,300 145.85 9,733 171.72 n/a n/a n/a
2014-08-14 2014-06-30 13F LAM RESEARCH Cmn Call 53,000 -7.02 3,582 14.26 n/a n/a n/a
2014-05-15 2014-03-31 13F LAM RESEARCH Cmn Call 57,000 19.00 3,135 20.21 n/a n/a n/a
2014-02-14 2013-12-31 13F LAM RESEARCH Cmn Call 47,900 -37.06 2,608 -33.06 n/a n/a n/a
2013-11-14 2013-09-30 13F LAM RESEARCH Cmn Call 76,100 63.66 3,896 88.94 n/a n/a n/a
2013-08-14 2013-06-30 13F LAM RESEARCH Cmn Call 46,500 2,062 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
(%)
2026-05-15 2026-03-31 13F LAM RESEARCH COM NEW Put 1,978,700 -52.72 422,769 -40.98 n/a n/a n/a
2026-02-17 2025-12-31 13F LAM RESEARCH COM NEW Put 4,184,700 43.33 716,337 83.24 n/a n/a n/a
2025-11-14 2025-09-30 13F LAM RESEARCH COM NEW Put 2,919,600 11.81 390,934 53.81 n/a n/a n/a
2025-08-14 2025-06-30 13F LAM RESEARCH COM NEW Put 2,611,100 10.41 254,164 47.83 n/a n/a n/a
2025-05-15 2025-03-31 13F LAM RESEARCH COM NEW Put 2,365,000 -26.78 171,936 -26.30 n/a n/a n/a
2025-02-14 2024-12-31 13F LAM RESEARCH COM NEW Put 3,229,800 233,288 n/a n/a n/a
2017-01-31 2016-09-30 13F/A LAM RESEARCH Cmn Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-01-31 2016-06-30 13F/A LAM RESEARCH Cmn Put 135,600 37.25 11,399 39.68 n/a n/a n/a
2016-08-12 2016-06-30 13F LAM RESEARCH Cmn Put 135,600 11,399 n/a n/a n/a
2017-01-31 2016-03-31 13F/A LAM RESEARCH Cmn Put 98,800 -60.46 8,161 -58.88 n/a n/a n/a
2016-05-13 2016-03-31 13F LAM RESEARCH Cmn Put 98,800 8,161 n/a n/a n/a
2017-01-31 2015-12-31 13F/A LAM RESEARCH Cmn Put 249,900 46.91 19,847 78.61 n/a n/a n/a
2016-02-12 2015-12-31 13F LAM RESEARCH Cmn Put 249,900 19,847 n/a n/a n/a
2015-11-16 2015-09-30 13F LAM RESEARCH Cmn Put 170,100 5.33 11,112 -15.42 n/a n/a n/a
2015-08-14 2015-06-30 13F LAM RESEARCH Cmn Put 161,500 33.91 13,138 55.11 n/a n/a n/a
2015-05-15 2015-03-31 13F LAM RESEARCH Cmn Put 120,600 -22.84 8,470 -31.70 n/a n/a n/a
2015-02-17 2014-12-31 13F LAM RESEARCH Cmn Put 156,300 29.60 12,401 37.65 n/a n/a n/a
2014-11-14 2014-09-30 13F LAM RESEARCH Cmn Put 120,600 86.40 9,009 106.06 n/a n/a n/a
2014-08-14 2014-06-30 13F LAM RESEARCH Cmn Put 64,700 30.18 4,372 59.91 n/a n/a n/a
2014-05-15 2014-03-31 13F LAM RESEARCH Cmn Put 49,700 -53.46 2,734 -52.98 n/a n/a n/a
2014-02-14 2013-12-31 13F LAM RESEARCH Cmn Put 106,800 51.27 5,815 60.90 n/a n/a n/a
2013-11-14 2013-09-30 13F LAM RESEARCH Cmn Put 70,600 45.87 3,614 68.41 n/a n/a n/a
2013-08-14 2013-06-30 13F LAM RESEARCH Cmn Put 48,400 2,146 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.