One Stop Systems, Inc.
US ˙ NasdaqCM ˙ US68247W1099

SecurityOSS / One Stop Systems, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership356,676 shares
Latest Disclosed Value $ 2,700,037
Citadel Advisors Llc ownership in OSS / One Stop Systems, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 356,676 shares of One Stop Systems, Inc. (US:OSS) valued at $2,700,037 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 145,676 shares of One Stop Systems, Inc.. This represents a change in shares of 144.84% during the quarter. The current value of the position is $6,024,258 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (OSS) in the form of stock options. The firm currently holds call options representing 174,200 of underlying shares valued at $1,318,694 USD and put options representing 214,100 of underlying shares valued at $1,620,737 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.

OSS / One Stop Systems, 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)
2026-05-15 2026-03-31 13F ONE STOP SYS COM 68247W109 356,676 211,000 144.84 2,700 158.37 0.0004
2026-02-17 2025-12-31 13F ONE STOP SYS COM 68247W109 145,676 -719,263 -83.16 1,046 -77.46 0.0002
2025-11-14 2025-09-30 13F ONE STOP SYS COM 68247W109 864,939 711,401 463.34 4,636 750.64 0.0007
2025-08-14 2025-06-30 13F ONE STOP SYS COM 68247W109 153,538 123,107 404.54 545 678.57 0.0001
2025-05-15 2025-03-31 13F ONE STOP SYS COM 68247W109 30,431 -66,642 -68.65 71 -78.46 0.0000
2025-02-14 2024-12-31 13F ONE STOP SYS COM 68247W109 97,073 33,643 53.04 325 115.23 0.0001
2024-11-14 2024-09-30 13F ONE STOP SYS COM 68247W109 63,430 -16,862 -21.00 152 -21.76 0.0000
2024-08-14 2024-06-30 13F ONE STOP SYS COM 68247W109 80,292 79,425 9,160.90 194 9,550.00 0.0000
2024-05-15 2024-03-31 13F ONE STOP SYS COM 68247W109 867 -10,102 -92.10 3 -91.30 0.0000
2024-02-14 2023-12-31 13F ONE STOP SYS COM 68247W109 10,969 10,969 23 0.0000
2023-11-14 2023-09-30 13F ONE STOP SYS COM 68247W109 0 -32,942 -100.00 0 -100.00
2023-08-14 2023-06-30 13F ONE STOP SYS COM 68247W109 32,942 -3,605 -9.86 95 4.44 0.0000
2023-05-15 2023-03-31 13F ONE STOP SYS COM 68247W109 36,547 36,547 91 0.0000
2023-02-14 2022-12-31 13F ONE STOP SYS COM 68247W109 0 -10,958 -100.00 0 -100.00
2022-11-14 2022-09-30 13F ONE STOP SYS COM 68247W109 10,958 10,958 35 0.0000
2022-02-14 2021-12-31 13F ONE STOP SYS Cmn 68247W109 0 -26,757 -100.00 0 -100.00
2021-11-15 2021-09-30 13F ONE STOP SYS Cmn 68247W109 26,757 16,467 160.03 134 123.33 0.0000
2021-08-16 2021-06-30 13F ONE STOP SYS COM 68247W109 10,290 -15,285 -59.77 60 -62.96 0.0000
2021-05-21 2021-03-31 13F/A-1 ONE STOP SYS COM 68247W109 25,575 25,575 162 0.0000
2021-05-17 2021-03-31 13F ONE STOP SYS COM 68247W109 25,575 25,575 162 0.0000
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 ONE STOP SYS COM Call 174,200 1.34 1,319 6.81 n/a n/a n/a
2026-02-17 2025-12-31 13F ONE STOP SYS COM Call 171,900 670.85 1,234 936.97 n/a n/a n/a
2025-11-14 2025-09-30 13F ONE STOP SYS COM Call 22,300 -81.31 120 -71.87 n/a n/a n/a
2025-08-14 2025-06-30 13F ONE STOP SYS COM Call 119,300 2,740.48 424 4,600.00 n/a n/a n/a
2025-05-15 2025-03-31 13F ONE STOP SYS COM Call 4,200 121.05 10 50.00 n/a n/a n/a
2025-02-14 2024-12-31 13F ONE STOP SYS COM Call 1,900 -65.45 6 -53.85 n/a n/a n/a
2024-11-14 2024-09-30 13F ONE STOP SYS COM Call 5,500 61.76 13 62.50 n/a n/a n/a
2024-08-14 2024-06-30 13F ONE STOP SYS COM Call 3,400 -69.64 8 -77.78 n/a n/a n/a
2024-05-15 2024-03-31 13F ONE STOP SYS COM Call 11,200 37 n/a n/a n/a
2023-11-14 2023-09-30 13F ONE STOP SYS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-08-14 2023-06-30 13F ONE STOP SYS COM Call 30,000 2,207.69 86 2,766.67 n/a n/a n/a
2023-05-15 2023-03-31 13F ONE STOP SYS COM Call 1,300 3 n/a n/a n/a
2023-02-14 2022-12-31 13F ONE STOP SYS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-14 2022-09-30 13F ONE STOP SYS COM Call 12,500 40 n/a n/a n/a
2022-05-16 2022-03-31 13F ONE STOP SYS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-14 2021-12-31 13F ONE STOP SYS COM Call 35,300 175 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 ONE STOP SYS COM Put 214,100 202.40 1,621 218.90 n/a n/a n/a
2026-02-17 2025-12-31 13F ONE STOP SYS COM Put 70,800 -7.09 508 24.51 n/a n/a n/a
2025-11-14 2025-09-30 13F ONE STOP SYS COM Put 76,200 418.37 408 684.62 n/a n/a n/a
2025-08-14 2025-06-30 13F ONE STOP SYS COM Put 14,700 -36.64 52 -1.89 n/a n/a n/a
2025-05-15 2025-03-31 13F ONE STOP SYS COM Put 23,200 -7.20 54 -36.14 n/a n/a n/a
2025-02-14 2024-12-31 13F ONE STOP SYS COM Put 25,000 36.61 84 93.02 n/a n/a n/a
2024-11-14 2024-09-30 13F ONE STOP SYS COM Put 18,300 117.86 44 115.00 n/a n/a n/a
2024-08-14 2024-06-30 13F ONE STOP SYS COM Put 8,400 833.33 20 900.00 n/a n/a n/a
2024-05-15 2024-03-31 13F ONE STOP SYS COM Put 900 800.00 3 n/a n/a n/a
2024-02-14 2023-12-31 13F ONE STOP SYS COM Put 100 0 n/a n/a n/a
2023-11-14 2023-09-30 13F ONE STOP SYS COM Put 0 -100.00 0 n/a n/a n/a
2023-08-14 2023-06-30 13F ONE STOP SYS COM Put 300 50.00 1 n/a n/a n/a
2023-05-15 2023-03-31 13F ONE STOP SYS COM Put 200 0 n/a n/a n/a
2022-08-15 2022-06-30 13F ONE STOP SYS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-16 2022-03-31 13F ONE STOP SYS COM Put 17,200 -43.97 66 -56.58 n/a n/a n/a
2022-02-14 2021-12-31 13F ONE STOP SYS COM Put 30,700 -28.60 152 -29.63 n/a n/a n/a
2021-11-15 2021-09-30 13F ONE STOP SYS Cmn Put 43,000 -5.91 216 -18.49 n/a n/a n/a
2021-08-16 2021-06-30 13F ONE STOP SYS COM Put 45,700 265 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.