ON Semiconductor Corporation
US ˙ NasdaqGS ˙ US6821891057

SecurityON / ON Semiconductor Corporation
InstitutionCalamos Advisors LLC
Latest Disclosed Ownership106,728 shares
Latest Disclosed Value $ 6,608,598
Calamos Advisors LLC ownership in ON / ON Semiconductor Corporation

On May 4, 2026 - Calamos Advisors LLC filed a 13F-HR form disclosing ownership of 106,728 shares of ON Semiconductor Corporation (US:ON) valued at $6,608,598 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 29, 2026 disclosing 106,728 shares of ON Semiconductor Corporation. This represents a change in shares of 0.00% during the quarter. The current value of the position is $12,514,925 USD.

Calamos Advisors LLC has a history of taking positions in derivatives of the underlying security (ON) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 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.

ON / ON Semiconductor 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)
2026-05-04 2026-03-31 13F ON SEMICONDUCTOR COM 682189105 106,728 0 0.00 6,609 14.35 0.0233
2026-01-29 2025-12-31 13F ON SEMICONDUCTOR COM 682189105 106,728 -4,335 -3.90 5,779 5.53 0.0216
2025-10-20 2025-09-30 13F ON SEMICONDUCTOR COM 682189105 111,063 0 0.00 5,477 -5.91 0.0202
2025-08-08 2025-06-30 13F ON SEMICONDUCTOR COM 682189105 111,063 0 0.00 5,821 28.79 0.0229
2025-04-29 2025-03-31 13F ON SEMICONDUCTOR COM 682189105 111,063 1,237 1.13 4,519 -34.73 0.0197
2025-01-24 2024-12-31 13F ON SEMICONDUCTOR COM 682189105 109,826 0 0.00 6,925 -13.17 0.0290
2024-11-07 2024-09-30 13F ON SEMICONDUCTOR COM 682189105 109,826 -2,695 -2.40 7,974 3.38 0.0345
2024-07-25 2024-06-30 13F ON SEMICONDUCTOR COM 682189105 112,521 -4,107 -3.52 7,713 -10.07 0.0343
2024-05-08 2024-03-31 13F ON SEMICONDUCTOR COM 682189105 116,628 -2,933 -2.45 8,578 -14.11 0.0406
2024-01-31 2023-12-31 13F ON SEMICONDUCTOR COM 682189105 119,561 -1,561 -1.29 9,987 -11.30 0.0484
2023-10-26 2023-09-30 13F ON SEMICONDUCTOR COM 682189105 121,122 0 0.00 11,258 -1.72 0.0585
2023-07-28 2023-06-30 13F ON SEMICONDUCTOR COM 682189105 121,122 0 0.00 11,456 14.89 0.0567
2023-05-04 2023-03-31 13F ON SEMICONDUCTOR COM 682189105 121,122 -15,657 -11.45 9,971 16.88 0.0487
2023-01-26 2022-12-31 13F ON SEMICONDUCTOR COM 682189105 136,779 136,779 8,531 0.0400
2022-10-24 2022-09-30 13F ON SEMICONDUCTOR COM 682189105 0 -26,923 -100.00 0 -100.00
2022-08-01 2022-06-30 13F ON SEMICONDUCTOR COM 682189105 26,923 26,923 1,354 0.0058
2022-02-01 2021-12-31 13F ON SEMICONDUCTOR COM 682189105 0 -14,753 -100.00 0 -100.00
2021-10-26 2021-09-30 13F ON SEMICONDUCTOR COM 682189105 14,753 14,753 675 0.0029
2021-07-22 2021-06-30 13F ON SEMICONDUCTOR COM 682189105 0 -28,317 -100.00 0 -100.00
2021-04-12 2021-03-31 13F ON SEMICONDUCTOR COM 682189105 28,317 28,317 1,178 0.0064
2019-08-07 2019-06-30 13F ON SEMICONDUCTOR COMMON STOCK 682189105 0 -22,000 -100.00 0 -100.00
2019-04-12 2019-03-31 13F ON SEMICONDUCTOR COMMON STOCK 682189105 22,000 22,000 453 0.0028
2018-04-13 2018-03-31 13F ON SEMICONDUCTOR COMMON STOCK 682189105 0 -50,700 -100.00 0 -100.00
2018-02-13 2017-12-31 13F ON SEMICONDUCTOR COMMON STOCK 682189105 50,700 -35,700 -41.32 1,062 -33.46 0.0054
2017-10-25 2017-09-30 13F ON SEMICONDUCTOR COMMON STOCK 682189105 86,400 -11,800 -12.02 1,596 15.74 0.0123
2017-08-09 2017-06-30 13F ON SEMICONDUCTOR COMMON STOCK 682189105 98,200 -810,112 -89.19 1,379 -90.20 0.0102
2017-04-20 2017-03-31 13F ON SEMICONDUCTOR COMMON STOCK 682189105 908,312 908,312 14,070 -81.98 0.1108
2015-05-13 2015-03-31 13F ON SEMICONDUCTOR COMMON STOCK 682189105 0 -52,025 -100.00 0 -100.00
2015-02-13 2014-12-31 13F ON SEMICONDUCTOR COMMON STOCK 682189105 52,025 -2,580 -4.72 527 7.99 0.0035
2014-11-14 2014-09-30 13F ON SEMICONDUCTOR COMMON STOCK 682189105 54,605 54,605 -6.18 488 14.82 0.0033
2014-02-14 2013-12-31 13F ON SEMICONDUCTOR COMMON STOCK 682189105 0 -58,200 -100.00 0 -100.00
2013-11-14 2013-09-30 13F ON SEMICONDUCTOR COMMON STOCK 682189105 58,200 -31,400 -35.04 425 -41.30 0.0027
2013-08-12 2013-06-30 13F ON SEMICONDUCTOR COMMON STOCK 682189105 89,600 89,600 724 0.0047
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
(%)
2022-10-24 2022-09-30 13F ON SEMICONDUCTOR COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-08-01 2022-06-30 13F ON SEMICONDUCTOR COM Call 98,000 4,930 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.