Form 144
Large Proposed Insider Sale
2026-06-01
MPWR Form 144 filed for proposed insider sale by THEODORE BERNHARD BLEGEN (3,001 shares) ~$9.25M
THEODORE BERNHARD BLEGEN filed a Form 144 with the SEC indicating intent to sell MPWR (MONOLITHIC POWER SYSTEMS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4. The proposed dollar value is large enough to merit attention.
Filing: Form 144 (Proposed Sale Notice)
Insider: THEODORE BERNHARD BLEGEN
Shares: 3,001
Est. Value: $9.25M
Form 4
Insider Selling
2026-05-29
MPWR insider Tseng Saria (EVP & General Counsel) sold 7,565 shares (~$12.86M)
Tseng Saria, listed as EVP & General Counsel at MONOLITHIC POWER SYSTEMS INC, reported an open-market sale of 7,565 MPWR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
Filing: Form 4 (Insider Transaction)
Insider: Tseng Saria (EVP & General Counsel)
Shares: 7,565
Est. Value: $12.86M
Form 4
Insider Selling
2026-05-28
MPWR insider DEAN ROBERT W II (Interim CFO) sold 22 shares (~$36.3K)
DEAN ROBERT W II, listed as Interim CFO at MONOLITHIC POWER SYSTEMS INC, reported an open-market sale of 22 MPWR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
Filing: Form 4 (Insider Transaction)
Insider: DEAN ROBERT W II (Interim CFO)
Shares: 22
Est. Value: $36.3K
Form 144
Large Proposed Insider Sale
2026-05-28
MPWR Form 144 filed for proposed insider sale by SARIA TSENG (7,565 shares) ~$25.72M
SARIA TSENG filed a Form 144 with the SEC indicating intent to sell MPWR (MONOLITHIC POWER SYSTEMS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4. The proposed dollar value is large enough to merit attention.
Filing: Form 144 (Proposed Sale Notice)
Insider: SARIA TSENG
Shares: 7,565
Est. Value: $25.72M
Form 4
Insider Selling
2026-05-27
MPWR insider Zhou Jeff (Director) sold 486 shares (~$816.5K)
Zhou Jeff, listed as Director at MONOLITHIC POWER SYSTEMS INC, reported an open-market sale of 486 MPWR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
Filing: Form 4 (Insider Transaction)
Insider: Zhou Jeff (Director)
Shares: 486
Est. Value: $816.5K
Form 4
Insider Selling
2026-05-27
MPWR insider Tseng Saria (EVP & General Counsel) sold 5,000 shares (~$7.93M)
Tseng Saria, listed as EVP & General Counsel at MONOLITHIC POWER SYSTEMS INC, reported an open-market sale of 5,000 MPWR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
Filing: Form 4 (Insider Transaction)
Insider: Tseng Saria (EVP & General Counsel)
Shares: 5,000
Est. Value: $7.93M
Form 144
Proposed Insider Sale
2026-05-26
MPWR Form 144 filed for proposed insider sale by DEAN ROBERT W II (22 shares) ~$71.8K
DEAN ROBERT W II filed a Form 144 with the SEC indicating intent to sell MPWR (MONOLITHIC POWER SYSTEMS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.
Filing: Form 144 (Proposed Sale Notice)
Insider: DEAN ROBERT W II
Shares: 22
Est. Value: $71.8K
Form 144
Proposed Insider Sale
2026-05-26
MPWR Form 144 filed for proposed insider sale by JEFF ZHOU (486 shares) ~$1.63M
JEFF ZHOU filed a Form 144 with the SEC indicating intent to sell MPWR (MONOLITHIC POWER SYSTEMS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.
Filing: Form 144 (Proposed Sale Notice)
Insider: JEFF ZHOU
Shares: 486
Est. Value: $1.63M
Form 144
Large Proposed Insider Sale
2026-05-22
MPWR Form 144 filed for proposed insider sale by SARIA TSENG (5,000 shares) ~$15.86M
SARIA TSENG filed a Form 144 with the SEC indicating intent to sell MPWR (MONOLITHIC POWER SYSTEMS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4. The proposed dollar value is large enough to merit attention.
Filing: Form 144 (Proposed Sale Notice)
Insider: SARIA TSENG
Shares: 5,000
Est. Value: $15.86M
Form 4
Insider Selling
2026-05-20
MPWR insider Hsing Michael (Director, CEO) sold 40,000 shares (~$59.31M)
Hsing Michael, listed as Director, CEO at MONOLITHIC POWER SYSTEMS INC, reported an open-market sale of 40,000 MPWR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
Filing: Form 4 (Insider Transaction)
Insider: Hsing Michael (Director, CEO)
Shares: 40,000
Est. Value: $59.31M
Form 4
Insider Selling
2026-05-20
MPWR insider DEAN ROBERT W II (Interim CFO) sold 4 shares (~$6.3K)
DEAN ROBERT W II, listed as Interim CFO at MONOLITHIC POWER SYSTEMS INC, reported an open-market sale of 4 MPWR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
Filing: Form 4 (Insider Transaction)
Insider: DEAN ROBERT W II (Interim CFO)
Shares: 4
Est. Value: $6.3K
Form 4
Insider Selling
2026-05-19
MPWR insider Sciammas Maurice (EVP, WW Sales & Marketing) sold 12,000 shares (~$18.74M)
Sciammas Maurice, listed as EVP, WW Sales & Marketing at MONOLITHIC POWER SYSTEMS INC, reported an open-market sale of 12,000 MPWR shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.
Filing: Form 4 (Insider Transaction)
Insider: Sciammas Maurice (EVP, WW Sales & Marketing)
Shares: 12,000
Est. Value: $18.74M
Form 144
Proposed Insider Sale
2026-05-18
MPWR Form 144 filed for proposed insider sale by DEAN ROBERT W II (4 shares) ~$12.5K
DEAN ROBERT W II filed a Form 144 with the SEC indicating intent to sell MPWR (MONOLITHIC POWER SYSTEMS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.
Filing: Form 144 (Proposed Sale Notice)
Insider: DEAN ROBERT W II
Shares: 4
Est. Value: $12.5K
Form 144
Large Proposed Insider Sale
2026-05-18
MPWR Form 144 filed for proposed insider sale by MICHAEL HSING (40,000 shares) ~$118.62M
MICHAEL HSING filed a Form 144 with the SEC indicating intent to sell MPWR (MONOLITHIC POWER SYSTEMS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4. The proposed dollar value is large enough to merit attention.
Filing: Form 144 (Proposed Sale Notice)
Insider: MICHAEL HSING
Shares: 40,000
Est. Value: $118.62M
Form 4
Tax / Compensation Filing
2026-05-15
MPWR insider Form 4 filed for equity award, exercise, or tax withholding
Sciammas Maurice (EVP, WW Sales & Marketing) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.
Filing: Form 4 (Insider Transaction)
Insider: Sciammas Maurice (EVP, WW Sales & Marketing)
Shares: 3,126