Mats Wahlstrom
Insider
Activist
First SEC filing: Aug. 1, 2025 · Latest: June 9, 2026
Insider at
Insider transactions
1 buys (P)
0 sells (S)
Net: $151,800
Avg return of open purchases vs close of 2026-10-23: 41.9%
Price change vs the latest weekly close (updated to the current quote in your browser when available), split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| June 5, 2026 | CHRS | A | 30,000 | · | · | 30,000 Direct | · | Acquired | |
| June 5, 2026 | CHRS | A | 60,000 | · | · | 60,000 Direct | · | Acquired | |
| May 15, 2026 | TLSI | P | 60,000 | $2.53 | $151,800 | 147,555 Direct | +68.53% | Acquired | 41.9% (price as of ) |
| May 14, 2026 | TLSI | A | 37,602 | · | · | 53,329 Direct | +239.09% | Acquired | |
| May 14, 2026 | TLSI | A | 34,226 | · | · | 87,555 Direct | +64.18% | Acquired | |
| May 14, 2026 | TLSI | A | 75,204 | · | · | 276,149 Direct | +37.43% | Acquired | |
| June 12, 2025 | TLSI | A | 15,000 | · | · | 200,945 Direct | +8.07% | Acquired | |
| June 12, 2025 | CHRS | A | 112,000 | · | · | 112,000 Direct | · | Acquired | |
| May 23, 2025 | CHRS | S | 99,988 | $0.74 | $73,991 | 0 Indirect | -100.00% | Disposed | 36.5% (price as of ) |
| Feb. 10, 2025 | TLSI | J | 44,750 | · | · | 94,750 Indirect | +89.50% | Acquired | |
| Dec. 17, 2024 | TLSI | A | 25,188 | $3.97 | $99,996 | 40,915 Direct | +160.16% | Acquired | -9.6% (price as of ) |
| Nov. 22, 2024 | TLSI | P | 5,000 | $4.55 | $22,750 | 15,727 Direct | +46.61% | Acquired | -21.1% (price as of ) |
| Nov. 21, 2024 | TLSI | P | 8,687 | $4.44 | $38,570 | 10,727 Direct | +425.83% | Acquired | -19.1% (price as of ) |
| Nov. 20, 2024 | TLSI | P | 2,040 | $4.16 | $8,486 | 2,040 Direct | · | Acquired | -13.7% (price as of ) |
| Aug. 13, 2024 | TLSI | A | 15,000 | · | · | 15,000 Direct | · | Acquired | |
| June 3, 2024 | CHRS | A | 112,000 | · | · | 112,000 Direct | · | Acquired | |
| Feb. 9, 2024 | CHRS | G | 99,988 | · | · | 0 Direct | -100.00% | Disposed | |
| Feb. 9, 2024 | CHRS | G | 99,988 | · | · | 99,988 Indirect | · | Acquired | |
| Feb. 1, 2024 | CHRS | M | 14,997 | $1.67 | $25,045 | 54,997 Direct | +37.49% | Acquired | -39.5% (price as of ) |
| Feb. 1, 2024 | CHRS | M | 44,991 | $1.67 | $75,135 | 99,988 Direct | +81.81% | Acquired | -39.5% (price as of ) |
| Feb. 1, 2024 | CHRS | M | 14,997 | · | · | 0 Direct | -100.00% | Disposed | |
| Feb. 1, 2024 | CHRS | M | 44,991 | · | · | 0 Direct | -100.00% | Disposed | |
| Aug. 10, 2023 | TLSI | A | 35,000 | · | · | 35,000 Direct | · | Acquired | |
| June 7, 2023 | CHRS | A | 38,250 | · | · | 38,250 Direct | · | Acquired | |
| Feb. 28, 2022 | CHRS | A | 29,994 | $2.08 | $62,388 | 40,000 Direct | +299.76% | Acquired | -51.4% (price as of ) |
| Feb. 28, 2022 | CHRS | M | 29,994 | · | · | 0 Direct | · | Acquired | |
| Feb. 25, 2022 | CHRS | A | 10,006 | $11.64 | $116,470 | 10,006 Direct | · | Acquired | -91.3% (price as of ) |
| Jan. 7, 2022 | CHRS | A | 27,000 | · | · | 27,000 Direct | · | Acquired | |
| Jan. 7, 2022 | CHRS | A | 27,000 | · | · | 27,000 Direct | · | Acquired | |
| Jan. 11, 2021 | CHRS | A | 20,000 | · | · | 20,000 Direct | · | Acquired | |
| June 17, 2020 | CHRS | S | 200,000 | $17.15 | $3,430,000 | 0 Indirect | -100.00% | Disposed | -94.1% (price as of ) |
| March 3, 2020 | CHRS | S | 113,844 | $20.09 | $2,287,126 | 204,222 Indirect | -35.79% | Disposed | -95.0% (price as of ) |
| March 3, 2020 | CHRS | S | 4,222 | $20.89 | $88,198 | 200,000 Indirect | -2.07% | Disposed | -95.2% (price as of ) |
| Jan. 10, 2020 | CHRS | A | 20,000 | · | · | 20,000 Direct | · | Acquired | |
| May 31, 2019 | CHRS | J | 178,528 | · | · | 0 Indirect | -100.00% | Disposed | |
| May 31, 2019 | CHRS | J | 98,152 | · | · | 318,066 Indirect | +44.63% | Acquired | |
| Jan. 11, 2019 | CHRS | A | 20,000 | · | · | 20,000 Direct | · | Acquired | |
| Feb. 1, 2018 | CHRS | A | 20,000 | · | · | 20,000 Direct | · | Acquired | |
| May 17, 2017 | CHRS | A | 20,000 | · | · | 20,000 Direct | · | Acquired | |
| May 9, 2017 | CHRS | J | 200,000 | · | · | 178,528 Indirect | -52.84% | Disposed | |
| May 9, 2017 | CHRS | J | 109,957 | · | · | 219,914 Indirect | +100.00% | Acquired | |
| Feb. 22, 2017 | CHRS | J | 200,000 | · | · | 378,528 Indirect | -34.57% | Disposed | |
| Feb. 22, 2017 | CHRS | J | 109,957 | · | · | 109,957 Indirect | · | Acquired | |
| Dec. 8, 2016 | CHRS | S | 46,190 | $27.52 | $1,271,149 | 0 Indirect | -100.00% | Disposed | -96.3% (price as of ) |
| Dec. 7, 2016 | CHRS | S | 7,393 | $27.50 | $203,308 | 46,190 Indirect | -13.80% | Disposed | -96.3% (price as of ) |
| May 24, 2016 | CHRS | A | 10,000 | · | · | 10,000 Direct | · | Acquired | |
| Feb. 29, 2016 | CHRS | P | 1,000,000 | $22.35 | $22,350,000 | 1,000,000 Indirect | · | Acquired | |
| Feb. 29, 2016 | CHRS | P | None | $22.35 | · | · Indirect | · | Acquired | |
| Aug. 18, 2015 | CHRS | S | 6,372 | $33.50 | $213,462 | 578,528 Indirect | -1.09% | Disposed | -97.0% (price as of ) |
| Aug. 18, 2015 | CHRS | S | 6,373 | $33.50 | $213,496 | 578,527 Indirect | -1.09% | Disposed | -97.0% (price as of ) |
| Aug. 17, 2015 | CHRS | S | 8,028 | $33.91 | $272,229 | 584,900 Indirect | -1.35% | Disposed | -97.0% (price as of ) |
| Aug. 14, 2015 | CHRS | S | 116,554 | $34.24 | $3,990,809 | 592,928 Indirect | -16.43% | Disposed | -97.1% (price as of ) |
| April 1, 2015 | CHRS | A | 20,000 | · | · | 20,000 Direct | · | Acquired | |
| April 1, 2015 | CHRS | A | 75,000 | · | · | 75,000 Direct | · | Acquired | |
| April 1, 2015 | CHRS | A | 20,000 | · | · | 20,000 Direct | · | Acquired | |
| April 1, 2015 | CHRS | A | 75,000 | · | · | 75,000 Direct | · | Acquired | |
| Dec. 23, 2014 | CHRS | J | 221,538 | · | · | 0 Indirect | -100.00% | Disposed | |
| Dec. 23, 2014 | CHRS | J | 114,639 | · | · | 709,482 Indirect | +19.27% | Acquired | |
| Nov. 12, 2014 | CHRS | C | 194,889 | · | · | 194,889 Indirect | · | Acquired | |
| Nov. 12, 2014 | CHRS | C | 26,649 | · | · | 221,538 Indirect | +13.67% | Acquired | |
| Nov. 12, 2014 | CHRS | C | 514,893 | · | · | 514,893 Indirect | · | Acquired | |
| Nov. 12, 2014 | CHRS | C | 79,950 | · | · | 594,843 Indirect | +15.53% | Acquired | |
| Nov. 12, 2014 | CHRS | C | 43,011 | · | · | 43,011 Indirect | · | Acquired | |
| Nov. 12, 2014 | CHRS | C | 10,572 | · | · | 53,583 Indirect | +24.58% | Acquired | |
| Nov. 12, 2014 | CHRS | C | 194,889 | · | · | 0 Indirect | -100.00% | Disposed | |
| Nov. 12, 2014 | CHRS | C | 26,649 | · | · | 0 Indirect | -100.00% | Disposed | |
| Nov. 12, 2014 | CHRS | C | 514,893 | · | · | 0 Indirect | -100.00% | Disposed | |
| Nov. 12, 2014 | CHRS | C | 79,950 | · | · | 0 Indirect | -100.00% | Disposed | |
| Nov. 12, 2014 | CHRS | C | 43,011 | · | · | 0 Indirect | -100.00% | Disposed | |
| Nov. 12, 2014 | CHRS | C | 10,572 | · | · | 0 Indirect | -100.00% | Disposed |
P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding
Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.
Derivative holdings (Form 4 Table II) Options, RSUs and convertible securities reported on Form 4 Table II.
| Date | Ticker | Security | Underlying | Exercise price | Expiration | Shares | A/D |
|---|---|---|---|---|---|---|---|
| June 5, 2026 | CHRS | Stock Option (Right to Buy) | Common Stock | $1.45 | June 5, 2036 | 60,000 | Acquired |
| May 14, 2026 | TLSI | Director Stock Option (right to buy) | Common Stock | $2.52 | May 13, 2036 | 75,204 | Acquired |
| June 12, 2025 | TLSI | Director Stock Option (right to buy) | Common Stock | $5.50 | June 11, 2035 | 15,000 | Acquired |
| June 12, 2025 | CHRS | Stock Option (Right to Buy) | Common Stock | $0.79 | June 12, 2035 | 112,000 | Acquired |
| Feb. 10, 2025 | TLSI | Series A Convertible Preferred Stock | Common Stock | · | · | 44,750 | Acquired |
| Aug. 13, 2024 | TLSI | Director stock option (right to buy) | Common Stock | $5.75 | Aug. 12, 2034 | 15,000 | Acquired |
| June 3, 2024 | CHRS | Stock Option (Right to Buy) | Common Stock | $1.76 | June 3, 2034 | 112,000 | Acquired |
| Feb. 1, 2024 | CHRS | Stock Option (Right to Buy) | Common Stock | $1.67 | March 10, 2024 | 14,997 | Disposed |
| Feb. 1, 2024 | CHRS | Stock Option (Right to Buy) | Common Stock | $1.67 | March 10, 2024 | 44,991 | Disposed |
| Aug. 10, 2023 | TLSI | Stock Option (right to buy) | Common Stock | $11.34 | Aug. 9, 2033 | 35,000 | Acquired |
| June 7, 2023 | CHRS | Stock Option (Right to Buy) | Common Stock | $5.38 | June 7, 2033 | 38,250 | Acquired |
| Feb. 28, 2022 | CHRS | Stock Option (Right to Buy) | Common Stock | $2.08 | Dec. 14, 2022 | 29,994 | Acquired |
| Jan. 7, 2022 | CHRS | Stock Option (Right to Buy) | Common Stock | · | Jan. 7, 2032 | 27,000 | Acquired |
| Jan. 7, 2022 | CHRS | Stock Option (Right to Buy) | Common Stock | $15.94 | Jan. 7, 2032 | 27,000 | Acquired |
| Jan. 11, 2021 | CHRS | Stock Option (Right to Buy) | Common Stock | $17.58 | Jan. 11, 2031 | 20,000 | Acquired |
| Jan. 10, 2020 | CHRS | Stock Option (Right to Buy) | Common Stock | $17.73 | Jan. 10, 2030 | 20,000 | Acquired |
| Jan. 11, 2019 | CHRS | Stock Option (Right to Buy) | Common Stock | $12.37 | Jan. 11, 2029 | 20,000 | Acquired |
| Feb. 1, 2018 | CHRS | Stock Option (Right to Buy) | Common Stock | $10.05 | Feb. 1, 2028 | 20,000 | Acquired |
| May 17, 2017 | CHRS | Stock Option (Right to Buy) | Common Stock | $23.80 | May 17, 2027 | 20,000 | Acquired |
| May 24, 2016 | CHRS | Stock Option (Right to Buy) | Common Stock | $18.28 | May 24, 2026 | 10,000 | Acquired |
| Feb. 29, 2016 | CHRS | 8.2% Senior Convertible Notes due 2022 [F3] | Common Stock | · | March 31, 2022 | 1,000,000 | Acquired |
| Feb. 29, 2016 | CHRS | 8.2% Senior Convertible Notes due 2022 [F3] | Common Stock | · | March 31, 2022 | · | Acquired |
| April 1, 2015 | CHRS | Stock Option (Right to Buy) | Common Stock | $29.00 | March 31, 2025 | 20,000 | Acquired |
| April 1, 2015 | CHRS | Stock Option (Right to Buy) | Common Stock | $29.00 | March 31, 2025 | 75,000 | Acquired |
| April 1, 2015 | CHRS | Stock Option (Right to Buy) | Common Stock | $29.00 | March 31, 2025 | 20,000 | Acquired |
| April 1, 2015 | CHRS | Stock Option (Right to Buy) | Common Stock | $29.00 | March 31, 2025 | 75,000 | Acquired |
| Nov. 12, 2014 | CHRS | Series B Preferred Stock | Common Stock | · | · | 194,889 | Disposed |
| Nov. 12, 2014 | CHRS | Series B Preferred Stock | Common Stock | · | · | 26,649 | Disposed |
| Nov. 12, 2014 | CHRS | Series B Preferred Stock | Common Stock | · | · | 514,893 | Disposed |
| Nov. 12, 2014 | CHRS | Series C Preferred Stock | Common Stock | · | · | 79,950 | Disposed |
| Nov. 12, 2014 | CHRS | Series C Preferred Stock | Common Stock | · | · | 43,011 | Disposed |
| Nov. 12, 2014 | CHRS | Series C Preferred Stock | Common Stock | · | · | 10,572 | Disposed |
Exercise/conversion price is blank when not applicable (e.g. RSUs).
Initial ownership (Form 3) 21 holdings
Securities held when first becoming an insider, per SEC Form 3.
| Date | Ticker | Security | Shares | Ownership |
|---|---|---|---|---|
| Aug. 14, 2023 | TLSI | Common Stock | 1,254,259 | Indirect |
| Aug. 14, 2023 | TLSI | Common Stock | 1,370,028 | Indirect |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Stock Option (right to buy) | · | Direct |
| Aug. 14, 2023 | TLSI | Series A Convertible Preferred Stock | 50,000 | Indirect |
| Nov. 6, 2014 | CHRS | Series B Preferred Stock | 194,889 | Indirect |
| Nov. 6, 2014 | CHRS | Series B Preferred Stock | 514,893 | Indirect |
| Nov. 6, 2014 | CHRS | Series B Preferred Stock | 43,011 | Indirect |
| Nov. 6, 2014 | CHRS | Series C Preferred Stock | 26,649 | Indirect |
| Nov. 6, 2014 | CHRS | Series C Preferred Stock | 79,950 | Indirect |
| Nov. 6, 2014 | CHRS | Series C Preferred Stock | 10,572 | Indirect |
| Nov. 6, 2014 | CHRS | Stock Option (Right to Buy) | 29,994 | Direct |
| Nov. 6, 2014 | CHRS | Stock Option (Right to Buy) | 14,997 | Direct |
| Nov. 6, 2014 | CHRS | Stock Option (Right to Buy) | 44,991 | Direct |
Holdings reported on Form 4 30 reported holdings
Positions listed on each Form 4 without a transaction in that filing (Table I and II holdings), newest filing first.
| Date | Ticker | Security | Shares | Exercise price | Expiration | Ownership |
|---|---|---|---|---|---|---|
| May 18, 2026 | TLSI | Common Stock | 1,444,447 | · | · | Indirect |
| May 18, 2026 | TLSI | Common Stock | 1,370,028 | · | · | Indirect |
| May 15, 2026 | TLSI | Common Stock | 1,444,447 | · | · | Indirect |
| May 15, 2026 | TLSI | Common Stock | 1,370,028 | · | · | Indirect |
| Dec. 19, 2024 | TLSI | Common Stock | 1,254,259 | · | · | Indirect |
| Dec. 19, 2024 | TLSI | Common Stock | 1,370,028 | · | · | Indirect |
| Nov. 25, 2024 | TLSI | Common Stock | 1,254,259 | · | · | Indirect |
| Nov. 25, 2024 | TLSI | Common Stock | 1,370,028 | · | · | Indirect |
| Nov. 22, 2024 | TLSI | Common Stock | 1,254,259 | · | · | Indirect |
| Nov. 22, 2024 | TLSI | Common Stock | 1,370,028 | · | · | Indirect |
| Jan. 30, 2019 | CHRS | Common Stock, $0.0001 par value | 178,528 | · | · | Indirect |
| Jan. 30, 2019 | CHRS | Common Stock, $0.0001 par value | 219,914 | · | · | Indirect |
| Feb. 5, 2018 | CHRS | Common Stock, $0.0001 par value | 178,528 | · | · | Indirect |
| Feb. 5, 2018 | CHRS | Common Stock, $0.0001 par value | 219,914 | · | · | Indirect |
| Dec. 9, 2016 | CHRS | Common Stock, $0.0001 par value | 578,528 | · | · | Indirect |
| May 26, 2016 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| May 26, 2016 | CHRS | Common Stock, $0.0001 par value | 578,528 | · | · | Indirect |
| May 26, 2016 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| May 26, 2016 | CHRS | Common Stock, $0.0001 par value | 578,528 | · | · | Indirect |
| May 26, 2016 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| March 11, 2016 | CHRS | Common Stock, $0.0001 par value | 578,527 | · | · | Indirect |
| March 11, 2016 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| Aug. 20, 2015 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| Aug. 19, 2015 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| Aug. 18, 2015 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| May 27, 2015 | CHRS | Common Stock, $0.0001 par value | 709,482 | · | · | Indirect |
| May 27, 2015 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| April 3, 2015 | CHRS | Common Stock, $0.0001 par value | 709,482 | · | · | Indirect |
| April 3, 2015 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |
| Dec. 24, 2014 | CHRS | Common Stock, $0.0001 par value | 53,583 | · | · | Indirect |