Richard K Prins
CIK 1047579 · View on SEC EDGAR ↗
Insider
First SEC filing: June 24, 2014 · Latest: June 24, 2014
On this page
Insider at
Insider transactions
0 buys (P)
2 sells (S)
Net:
$-275,103
+ 71 non-open-market transactions below
last 12 months, based on the transactions shown below
Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
71 other filings hidden
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| Aug. 11, 2026 | AMPH | S | 7,973 | $20.30 | $161,852 | 29,625 Direct | -21.21% | Disposed | 5.3% (price as of 2026-08-20) |
| Nov. 25, 2025 | AMPH | S | 4,179 | $27.10 | $113,251 | 35,183 Direct | -10.62% | Disposed | -21.1% (price as of 2026-08-20) |
| Nov. 12, 2024 | AMPH | S | 5,000 | $48.80 | $244,000 | 31,471 Direct | -13.71% | Disposed | -56.2% (price as of 2026-08-20) |
| Aug. 12, 2024 | AMPH | S | 17,101 | $43.07 | $736,540 | 33,971 Direct | -33.48% | Disposed | -50.4% (price as of 2026-08-20) |
| Nov. 17, 2023 | AMPH | S | 4,000 | $55.86 | $223,440 | 31,895 Direct | -11.14% | Disposed | -61.7% (price as of 2026-08-20) |
| Nov. 13, 2023 | AMPH | S | 5,000 | $52.50 | $262,500 | 35,895 Direct | -12.23% | Disposed | -59.3% (price as of 2026-08-20) |
| Aug. 18, 2023 | AMPH | S | 2,000 | $52.50 | $105,000 | 40,895 Direct | -4.66% | Disposed | -59.3% (price as of 2026-08-20) |
| Aug. 15, 2023 | AMPH | S | 4,163 | $57.39 | $238,915 | 42,895 Direct | -8.85% | Disposed | -62.7% (price as of 2026-08-20) |
| May 15, 2023 | AMPH | S | 5,000 | $43.50 | $217,500 | 44,342 Direct | -10.13% | Disposed | -50.9% (price as of 2026-08-20) |
| May 12, 2023 | AMPH | S | 5,000 | $42.06 | $210,300 | 47,342 Direct | -9.55% | Disposed | -49.2% (price as of 2026-08-20) |
| March 15, 2022 | AMPH | S | 10,000 | $34.02 | $340,200 | 45,179 Direct | -18.12% | Disposed | -37.2% (price as of 2026-08-20) |
| Dec. 10, 2021 | AMPH | S | 5,291 | $21.36 | $113,016 | 45,179 Direct | -10.48% | Disposed | 0.1% (price as of 2026-08-20) |
| Nov. 22, 2021 | AMPH | S | 5,000 | $21.22 | $106,100 | 45,179 Direct | -9.96% | Disposed | 0.8% (price as of 2026-08-20) |
| June 7, 2021 | AMPH | S | 5,000 | $18.70 | $93,500 | 39,160 Direct | -11.32% | Disposed | 14.3% (price as of 2026-08-20) |
| June 4, 2021 | AMPH | S | 5,000 | $18.77 | $93,850 | 39,160 Direct | -11.32% | Disposed | 13.9% (price as of 2026-08-20) |
| May 11, 2021 | AMPH | S | 15,827 | $18.90 | $299,130 | 39,160 Direct | -28.78% | Disposed | 13.1% (price as of 2026-08-20) |
| Aug. 11, 2020 | AMPH | S | 6,000 | $20.33 | $121,980 | 39,160 Direct | -13.29% | Disposed | 5.2% (price as of 2026-08-20) |
| May 12, 2020 | AMPH | S | 30,282 | $19.00 | $575,358 | 39,309 Direct | -43.51% | Disposed | 12.5% (price as of 2026-08-20) |
| Aug. 26, 2019 | AMPH | S | 3,618 | $22.60 | $81,767 | 39,309 Direct | -8.43% | Disposed | -5.4% (price as of 2026-08-20) |
| Aug. 23, 2019 | AMPH | S | 3,882 | $22.58 | $87,656 | 39,309 Direct | -8.99% | Disposed | -5.3% (price as of 2026-08-20) |
| Aug. 13, 2019 | AMPH | S | 10,000 | $20.78 | $207,800 | 39,309 Direct | -20.28% | Disposed | 2.9% (price as of 2026-08-20) |
| Dec. 14, 2018 | AMPH | S | 1,616 | $20.65 | $33,370 | 33,818 Direct | -4.56% | Disposed | 3.5% (price as of 2026-08-20) |
| Nov. 29, 2018 | AMPH | S | 5,000 | $20.50 | $102,500 | 35,434 Direct | -12.37% | Disposed | 4.3% (price as of 2026-08-20) |
| Nov. 14, 2018 | AMPH | S | 5,000 | $20.23 | $101,150 | 35,434 Direct | -12.37% | Disposed | 5.7% (price as of 2026-08-20) |
| Aug. 14, 2018 | AMPH | S | 10,000 | $17.82 | $178,200 | 35,434 Direct | -22.01% | Disposed | 20.0% (price as of 2026-08-20) |
| March 15, 2018 | AMPH | S | 16,598 | $19.90 | $330,300 | 28,844 Direct | -36.53% | Disposed | 7.4% (price as of 2026-08-20) |
| Aug. 15, 2017 | AMPH | S | 5,000 | $14.82 | $74,100 | 28,844 Direct | -14.77% | Disposed | 44.3% (price as of 2026-08-20) |
| Aug. 14, 2017 | AMPH | S | 5,000 | $14.80 | $74,000 | 28,844 Direct | -14.77% | Disposed | 44.5% (price as of 2026-08-20) |
| June 9, 2017 | AMPH | S | 10,000 | $17.07 | $170,700 | 28,844 Direct | -25.74% | Disposed | 25.2% (price as of 2026-08-20) |
Showing latest 100 of 149 transactions
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 1, 2026 | AMPH | Stock Option (right to buy) | Common Stock (17,365) | $18.42 | June 1, 2036 | 17,365 | Acquired |
| Nov. 25, 2025 | AMPH | Stock Option (right to buy) | Common Stock (4,179) | $16.69 | June 7, 2026 | 4,179 | Disposed |
| Nov. 12, 2024 | AMPH | Stock Option (right to buy) | Common Stock (2,500) | $16.69 | June 7, 2026 | 2,500 | Disposed |
| Aug. 12, 2024 | AMPH | Stock Option (right to buy) | Common Stock (3,915) | $20.03 | June 12, 2027 | 3,915 | Disposed |
| Aug. 12, 2024 | AMPH | Stock Option (right to buy) | Common Stock (6,004) | $20.08 | June 8, 2028 | 6,004 | Disposed |
| Aug. 12, 2024 | AMPH | Stock Option (right to buy) | Common Stock (7,182) | $19.52 | June 7, 2029 | 7,182 | Disposed |
| June 3, 2024 | AMPH | Stock Option (right to buy) | Common Stock (6,864) | $42.25 | June 3, 2034 | 6,864 | Acquired |
| June 5, 2023 | AMPH | Stock Option (right to buy) | Common Stock (7,016) | $46.01 | June 5, 2031 | 7,016 | Acquired |
| May 15, 2023 | AMPH | Stock option (right to buy) | Common Stock (5,000) | $16.69 | June 7, 2026 | 5,000 | Disposed |
| May 12, 2023 | AMPH | Stock option (right to buy) | Common Stock (5,000) | $16.69 | June 7, 2026 | 5,000 | Disposed |
| June 10, 2022 | AMPH | Stock Option (right to buy) | Common Stock (10,984) | $30.02 | June 10, 2030 | 10,984 | Acquired |
| March 15, 2022 | AMPH | Stock Option (right to buy) | Common Stock (10,000) | $17.11 | June 8, 2022 | 10,000 | Disposed |
| Dec. 10, 2021 | AMPH | Stock Option (right to buy) | Common Stock (5,291) | $17.11 | June 8, 2022 | 5,291 | Disposed |
| Nov. 22, 2021 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $17.11 | June 8, 2022 | 5,000 | Disposed |
| June 7, 2021 | AMPH | Stock Option (right to buy) | Common Stock (17,182) | $19.52 | June 7, 2029 | 17,182 | Acquired |
| June 7, 2021 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $16.43 | June 9, 2021 | 5,000 | Disposed |
| June 4, 2021 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $16.43 | June 9, 2021 | 5,000 | Disposed |
| May 11, 2021 | AMPH | Stock Option (right to buy) | Common Stock (15,827) | $16.43 | June 9, 2021 | 15,827 | Disposed |
| June 8, 2020 | AMPH | Stock Option (right to buy) | Common Stock (16,004) | $20.08 | June 8, 2028 | 16,004 | Acquired |
| May 12, 2020 | AMPH | Stock Option (right to buy) | Common Stock (30,282) | $15.11 | May 27, 2020 | 30,282 | Disposed |
| Aug. 26, 2019 | AMPH | Common Stock | Common Stock (3,618) | $15.11 | May 27, 2020 | 3,618 | Disposed |
| Aug. 23, 2019 | AMPH | Common Stock | Common Stock (3,882) | $15.11 | May 27, 2020 | 3,882 | Disposed |
| Aug. 13, 2019 | AMPH | Common Stock | Common Stock (10,000) | $15.11 | May 27, 2020 | 10,000 | Disposed |
| June 12, 2019 | AMPH | Stock Option (right to buy) | Common Stock (13,915) | $20.03 | June 12, 2027 | 13,915 | Acquired |
| Nov. 29, 2018 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $14.66 | Dec. 20, 2018 | 5,000 | Disposed |
| Nov. 14, 2018 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $14.66 | Dec. 20, 2018 | 5,000 | Disposed |
| Aug. 14, 2018 | AMPH | Stock Option (right to buy) | Common Stock (10,000) | $14.66 | Dec. 20, 2018 | 10,000 | Disposed |
| June 7, 2018 | AMPH | Stock Option (right to buy) | Common Stock (16,679) | $16.69 | June 7, 2026 | 16,679 | Acquired |
| March 15, 2018 | AMPH | Stock Option (right to buy) | Common Stock (16,598) | $14.66 | Dec. 20, 2018 | 16,598 | Disposed |
| Aug. 15, 2017 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $10.77 | Dec. 15, 2017 | 5,000 | Disposed |
| Aug. 14, 2017 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $10.77 | Dec. 15, 2017 | 5,000 | Disposed |
| June 9, 2017 | AMPH | Stock Option (right to buy) | Common Stock (10,000) | $10.77 | Dec. 15, 2017 | 10,000 | Disposed |
| June 8, 2017 | AMPH | Stock Option (right to buy) | Common Stock (20,291) | $17.11 | June 8, 2022 | 20,291 | Acquired |
| May 11, 2017 | AMPH | Stock Option (right to buy) | Common Stock (7,500) | $10.77 | Dec. 15, 2017 | 7,500 | Disposed |
| Nov. 11, 2016 | AMPH | Stock Option (right to buy) | Common Stock (5,000) | $10.77 | Dec. 15, 2017 | 5,000 | Disposed |
| Aug. 11, 2016 | AMPH | Stock Option (right to buy) | Common Stock (7,500) | $10.77 | Dec. 15, 2017 | 7,500 | Disposed |
| Aug. 11, 2016 | AMPH | Stock Option (right to buy) | Common Stock (3,898) | $14.23 | Dec. 10, 2016 | 3,898 | Disposed |
| Aug. 11, 2016 | AMPH | Stock Option (right to buy) | Common Stock (2,595) | $2.60 | Oct. 3, 2016 | 2,595 | Disposed |
| June 13, 2016 | AMPH | Stock Option (right to buy) | Common Stock (7,500) | $14.23 | Dec. 10, 2016 | 7,500 | Disposed |
| June 9, 2016 | AMPH | Stock Option (right to buy) | Common Stock (25,827) | $16.43 | June 9, 2021 | 25,827 | Acquired |
| Aug. 18, 2015 | AMPH | Stock Option (right to buy) | Common Stock (2,100) | $10.77 | Dec. 15, 2017 | 2,100 | Disposed |
| Aug. 17, 2015 | AMPH | Stock Option (right to buy) | Common Stock (5,400) | $10.77 | Dec. 15, 2017 | 5,400 | Disposed |
| May 27, 2015 | AMPH | Stock Option (right to buy) | Common Stock (47,782) | $15.11 | May 27, 2020 | 47,782 | Acquired |
| May 22, 2015 | AMPH | Stock Option (right to buy) | Common Stock (1,942) | $10.77 | Dec. 15, 2017 | 1,942 | Disposed |
| May 21, 2015 | AMPH | Stock Option (right to buy) | Common Stock (1,664) | $10.77 | Dec. 15, 2017 | 1,664 | Disposed |
| May 21, 2015 | AMPH | Stock Option (right to buy) | Common Stock (11,901) | $11.68 | Dec. 18, 2015 | 11,901 | Disposed |
| May 20, 2015 | AMPH | Stock Option (right to buy) | Common Stock (13,945) | $11.68 | Dec. 18, 2015 | 13,945 | Disposed |
| May 19, 2015 | AMPH | Stock Option (right to buy) | Common Stock (3,000) | $11.68 | Dec. 18, 2015 | 3,000 | Disposed |
Exercise/conversion price is blank when not applicable (e.g. RSUs).
Initial ownership (Form 3) 7 holdings
Securities held when first becoming an insider, per SEC Form 3.
| Date | Ticker | Security | Shares | Ownership |
|---|---|---|---|---|
| June 24, 2014 | AMPH | Common Stock | 27,958 | Direct |
| June 24, 2014 | AMPH | Common Stock | — | Direct |
| June 24, 2014 | AMPH | Stock Option (Right to Buy)→ Common Stock (28,846) | 28,846 | Direct |
| June 24, 2014 | AMPH | Stock Option (Right to Buy)→ Common Stock (2,595) | 2,595 | Direct |
| June 24, 2014 | AMPH | Stock Option (Right to Buy)→ Common Stock (11,398) | 11,398 | Direct |
| June 24, 2014 | AMPH | Stock Option (Right to Buy)→ Common Stock (51,106) | 51,106 | Direct |
| June 24, 2014 | AMPH | Stock Option (Right to Buy)→ Common Stock (36,598) | 36,598 | Direct |