SPDR Series Trust - State Street SPDR Bloomberg 1-3 Month T-Bill ETF
US ˙ ARCA ˙ US78468R6633

SecurityBIL / SPDR Series Trust - State Street SPDR Bloomberg 1-3 Month T-Bill ETF
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership9,915 shares
Latest Disclosed Value $ 908,611
Citadel Advisors Llc ownership in BIL / SPDR Series Trust - State Street SPDR Bloomberg 1-3 Month T-Bill ETF

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 9,915 shares of SPDR Series Trust - State Street SPDR Bloomberg 1-3 Month T-Bill ETF (US:BIL) valued at $908,611 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 0 shares of SPDR Series Trust - State Street SPDR Bloomberg 1-3 Month T-Bill ETF. The current value of the position is $906,330 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (BIL) in the form of stock options. The firm currently holds call options representing 2,900 of underlying shares valued at $265,756 USD and put options representing 48,100 of underlying shares valued at $4,407,884 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.

BIL / SPDR Series Trust - State Street SPDR Bloomberg 1-3 Month T-Bill ETF 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 SPDR SERIES TRUST STATE STREET SPD 78468R663 9,915 9,915 909 0.0001
2026-02-17 2025-12-31 13F SPDR SERIES TRUST BLOOMBERG 1-3 MO 78468R663 0 -24,944 -100.00 0 -100.00
2025-11-14 2025-09-30 13F SPDR SERIES TRUST BLOOMBERG 1-3 MO 78468R663 24,944 -135,496 -84.45 2,289 -84.45 0.0003
2025-08-14 2025-06-30 13F SPDR SERIES TRUST BLOOMBERG 1-3 MO 78468R663 160,440 83,180 107.66 14,717 107.66 0.0026
2025-05-15 2025-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 77,260 71,857 1,329.95 7,087 1,337.53 0.0013
2025-02-14 2024-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 5,403 -81,537 -93.79 494 -93.82 0.0001
2024-11-14 2024-09-30 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 86,940 -35,763 -29.15 7,982 -29.13 0.0015
2024-08-14 2024-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 122,703 -115,851 -48.56 11,262 -48.58 0.0023
2024-05-15 2024-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 238,554 238,554 21,899 0.0042
2024-02-14 2023-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 0 -155,219 -100.00 0 -100.00
2023-11-14 2023-09-30 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 155,219 65,974 73.92 14,252 73.93 0.0031
2023-08-14 2023-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 89,245 77,907 687.13 8,194 687.13 0.0017
2023-05-15 2023-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 11,338 11,138 5,569.00 1,041 5,683.33 0.0002
2023-02-14 2022-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 200 -31,957 -99.38 18 -99.39 0.0000
2022-11-14 2022-09-30 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 32,157 32,157 2,946 0.0007
2022-08-15 2022-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 0 -126,736 -100.00 0 -100.00
2022-05-16 2022-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO 78468R663 126,736 126,736 11,587 0.0024
2022-03-11 2021-09-30 13F/A-1 SPDR SER TR SPDR BLOOMBERG 78468R663 0 -90,008 -100.00 0 -100.00
2021-11-15 2021-09-30 13F SPDR SER TR SPDR BLOOMBERG 78468R663 0 -90,008 0
2021-08-16 2021-06-30 13F SPDR SER TR SPDR BLOOMBERG 78468R663 90,008 20,134 28.81 8,233 28.78 0.0018
2021-05-21 2021-03-31 13F/A-1 SPDR SER TR SPDR BLOOMBERG 78468R663 69,874 5,010 7.72 6,393 7.70 0.0016
2021-05-17 2021-03-31 13F SPDR SER TR SPDR BLOOMBERG 78468R663 69,874 5,010 6,393 0.0016
2021-02-16 2020-12-31 13F SPDR SER TR SPDR BLOOMBERG 78468R663 64,864 -152,333 -70.14 5,936 -70.14 0.0015
2020-11-16 2020-09-30 13F SPDR SER TR SPDR BLOOMBERG 78468R663 217,197 25,138 13.09 19,878 13.08 0.0056
2020-08-14 2020-06-30 13F SPDR SER TR Cmn 78468R663 192,059 -256,806 -57.21 17,579 -57.26 0.0063
2020-05-15 2020-03-31 13F SPDR SER TR Cmn 78468R663 448,865 412,352 1,129.33 41,129 1,132.14 0.0185
2020-02-14 2019-12-31 13F SPDR SERIES TRUST Cmn 78468R663 36,513 -172,011 -82.49 3,338 -82.52 0.0014
2019-11-14 2019-09-30 13F SPDR SERIES TRUST Cmn 78468R663 208,524 127,068 156.00 19,099 155.95 0.0090
2019-08-14 2019-06-30 13F SPDR SERIES TRUST Cmn 78468R663 81,456 -17,992 -18.09 7,462 -18.08 0.0034
2019-05-15 2019-03-31 13F SPDR SER TR Cmn 78468R663 99,448 99,448 9,109 0.0045
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 SPDR SERIES TRUST STATE STREET SPD Call 2,900 266 n/a n/a n/a
2025-05-15 2025-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO Call 500 -64.29 46 -64.84 n/a n/a n/a
2024-11-14 2024-09-30 13F SPDR SER TR BLOOMBERG 1-3 MO Call 1,400 -17.65 129 -17.95 n/a n/a n/a
2024-08-14 2024-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO Call 1,700 70.00 156 71.43 n/a n/a n/a
2024-05-15 2024-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO Call 1,000 11.11 92 10.98 n/a n/a n/a
2024-02-14 2023-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO Call 900 -62.50 82 -62.73 n/a n/a n/a
2023-11-14 2023-09-30 13F SPDR SER TR BLOOMBERG 1-3 MO Call 2,400 100.00 220 100.00 n/a n/a n/a
2023-08-14 2023-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO Call 1,200 -42.86 110 -42.71 n/a n/a n/a
2023-05-15 2023-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO Call 2,100 -8.70 193 -8.57 n/a n/a n/a
2023-02-14 2022-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO Call 2,300 210 n/a n/a n/a
2021-08-16 2021-06-30 13F SPDR SER TR SPDR BLOOMBERG Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-05-21 2021-03-31 13F/A SPDR SER TR SPDR BLOOMBERG Call 23,400 -22.77 2,141 -22.79 n/a n/a n/a
2021-05-17 2021-03-31 13F SPDR SER TR SPDR BLOOMBERG Call 23,400 2,141 n/a n/a n/a
2021-02-16 2020-12-31 13F SPDR SER TR SPDR BLOOMBERG Call 30,300 -21.30 2,773 -21.31 n/a n/a n/a
2020-11-16 2020-09-30 13F SPDR SER TR SPDR BLOOMBERG Call 38,500 -46.08 3,524 -46.07 n/a n/a n/a
2020-08-14 2020-06-30 13F SPDR SER TR Cmn Call 71,400 -33.21 6,535 -33.28 n/a n/a n/a
2020-05-15 2020-03-31 13F SPDR SER TR Cmn Call 106,900 126.96 9,795 127.47 n/a n/a n/a
2020-02-14 2019-12-31 13F SPDR SERIES TRUST Cmn Call 47,100 -43.59 4,306 -43.70 n/a n/a n/a
2019-11-14 2019-09-30 13F SPDR SERIES TRUST Cmn Call 83,500 32.54 7,648 32.52 n/a n/a n/a
2019-08-14 2019-06-30 13F SPDR SERIES TRUST Cmn Call 63,000 34.90 5,771 34.90 n/a n/a n/a
2019-05-15 2019-03-31 13F SPDR SER TR Cmn Call 46,700 14.74 4,278 14.94 n/a n/a n/a
2019-02-14 2018-12-31 13F SPDR SER TR Cmn Call 40,700 3,722 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 SPDR SERIES TRUST STATE STREET SPD Put 48,100 4,408 n/a n/a n/a
2025-08-14 2025-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO Put 1,100 0.00 101 0.00 n/a n/a n/a
2025-02-14 2024-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO Put 1,100 -60.71 101 -61.09 n/a n/a n/a
2024-11-14 2024-09-30 13F SPDR SER TR BLOOMBERG 1-3 MO Put 2,800 64.71 257 64.74 n/a n/a n/a
2024-08-14 2024-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO Put 1,700 -15.00 156 -14.75 n/a n/a n/a
2024-05-15 2024-03-31 13F SPDR SER TR BLOOMBERG 1-3 MO Put 2,000 -50.00 184 -49.86 n/a n/a n/a
2024-02-14 2023-12-31 13F SPDR SER TR BLOOMBERG 1-3 MO Put 4,000 -42.03 366 -42.34 n/a n/a n/a
2023-11-14 2023-09-30 13F SPDR SER TR BLOOMBERG 1-3 MO Put 6,900 666.67 634 671.95 n/a n/a n/a
2023-08-14 2023-06-30 13F SPDR SER TR BLOOMBERG 1-3 MO Put 900 83 n/a n/a n/a
2021-08-16 2021-06-30 13F SPDR SER TR SPDR BLOOMBERG Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-05-21 2021-03-31 13F/A SPDR SER TR SPDR BLOOMBERG Put 9,800 -88.74 897 -88.73 n/a n/a n/a
2021-05-17 2021-03-31 13F SPDR SER TR SPDR BLOOMBERG Put 9,800 897 n/a n/a n/a
2021-02-16 2020-12-31 13F SPDR SER TR SPDR BLOOMBERG Put 87,000 -40.41 7,962 -40.41 n/a n/a n/a
2020-11-16 2020-09-30 13F SPDR SER TR SPDR BLOOMBERG Put 146,000 -27.47 13,362 -27.48 n/a n/a n/a
2020-08-14 2020-06-30 13F SPDR SER TR Cmn Put 201,300 -5.76 18,425 -5.86 n/a n/a n/a
2020-05-15 2020-03-31 13F SPDR SER TR Cmn Put 213,600 58.93 19,572 59.28 n/a n/a n/a
2020-02-14 2019-12-31 13F SPDR SERIES TRUST Cmn Put 134,400 -15.89 12,288 -16.04 n/a n/a n/a
2019-11-14 2019-09-30 13F SPDR SERIES TRUST Cmn Put 159,800 -5.39 14,636 -5.41 n/a n/a n/a
2019-08-14 2019-06-30 13F SPDR SERIES TRUST Cmn Put 168,900 1,262.10 15,473 1,262.06 n/a n/a n/a
2019-05-15 2019-03-31 13F SPDR SER TR Cmn Put 12,400 -1.59 1,136 -1.39 n/a n/a n/a
2019-02-14 2018-12-31 13F SPDR SER TR Cmn Put 12,600 1,152 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.