HSING MICHAEL (CEO) sold 4.5% of their position (40K shares) of MONOLITHIC POWER SYSTEMS INC on the open market

Open‑market sale worth $59.31M — a minor trim. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 13 sales

HSING MICHAEL

Filed: 5/21/2026ACC: 0001214659-26-006625

InsiderHSING MICHAELCIK 1308676

→

IssuerMONOLITHIC POWER SYSTEMS INCCIK 1280452

DirectorOfficer· CEO

Since Jul 2018

-40K

Net shares

Net seller

$59.31M

Total sold

Open market trades

0B · 13S

Total transactions

40K disposed

Non-Derivative Transactions13

Common Stock

Direct

S · Sale

−3.42K

Price / share

$1.46K

Trade value

$5.01M

% of position

0.4%

5/18/2026

888.26K→884.84K

Common Stock

Direct

S · Sale

−5.82K

Price / share

$1.47K

Trade value

$8.54M

% of position

0.7%

5/18/2026

884.84K→879.02K

Common Stock

Direct

S · Sale

−5.05K

Price / share

$1.47K

Trade value

$7.44M

% of position

0.6%

5/18/2026

879.02K→873.97K

Common Stock

Direct

S · Sale

−4.08K

Price / share

$1.48K

Trade value

$6.03M

% of position

0.5%

5/18/2026

873.97K→869.89K

Common Stock

Direct

S · Sale

−5.74K

Price / share

$1.48K

Trade value

$8.51M

% of position

0.7%

5/18/2026

869.89K→864.15K

Common Stock

Direct

S · Sale

−6.69K

Price / share

$1.49K

Trade value

$9.94M

% of position

0.8%

5/18/2026

864.15K→857.46K

Common Stock

Direct

S · Sale

−862.00

Price / share

$1.49K

Trade value

$1.29M

% of position

0.1%

5/18/2026

857.46K→856.60K

Common Stock

Direct

S · Sale

−608.00

Price / share

$1.50K

Trade value

$911.67K

% of position

0.1%

5/18/2026

856.60K→855.99K

Common Stock

Direct

S · Sale

−2.93K

Price / share

$1.50K

Trade value

$4.40M

% of position

0.3%

5/18/2026

855.99K→853.07K

Common Stock

Direct

S · Sale

−3.77K

Price / share

$1.51K

Trade value

$5.68M

% of position

0.4%

5/18/2026

853.07K→849.30K

Common Stock

Direct

S · Sale

−551.00

Price / share

$1.51K

Trade value

$833.72K

% of position

0.1%

5/18/2026

849.30K→848.75K

Common Stock

Direct

S · Sale

−352.00

Price / share

$1.52K

Trade value

$534.39K

% of position

0.0%

5/18/2026

848.75K→848.39K

Common Stock

Direct

S · Sale

−130.00

Price / share

$1.52K

Trade value

$197.79K

% of position

0.0%

5/18/2026

848.39K→848.26K

Total

Net shares

−40K

Net value

-$59.31M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Common Stock Direct	5/18/2026	S · Sale	−3.42K	$1.46K	$5.01M	0.4%	888.26K	884.84K
Common Stock Direct	5/18/2026	S · Sale	−5.82K	$1.47K	$8.54M	0.7%	884.84K	879.02K
Common Stock Direct	5/18/2026	S · Sale	−5.05K	$1.47K	$7.44M	0.6%	879.02K	873.97K
Common Stock Direct	5/18/2026	S · Sale	−4.08K	$1.48K	$6.03M	0.5%	873.97K	869.89K
Common Stock Direct	5/18/2026	S · Sale	−5.74K	$1.48K	$8.51M	0.7%	869.89K	864.15K
Common Stock Direct	5/18/2026	S · Sale	−6.69K	$1.49K	$9.94M	0.8%	864.15K	857.46K
Common Stock Direct	5/18/2026	S · Sale	−862.00	$1.49K	$1.29M	0.1%	857.46K	856.60K
Common Stock Direct	5/18/2026	S · Sale	−608.00	$1.50K	$911.67K	0.1%	856.60K	855.99K
Common Stock Direct	5/18/2026	S · Sale	−2.93K	$1.50K	$4.40M	0.3%	855.99K	853.07K
Common Stock Direct	5/18/2026	S · Sale	−3.77K	$1.51K	$5.68M	0.4%	853.07K	849.30K
Common Stock Direct	5/18/2026	S · Sale	−551.00	$1.51K	$833.72K	0.1%	849.30K	848.75K
Common Stock Direct	5/18/2026	S · Sale	−352.00	$1.52K	$534.39K	0.0%	848.75K	848.39K
Common Stock Direct	5/18/2026	S · Sale	−130.00	$1.52K	$197.79K	0.0%	848.39K	848.26K
Total			−40K		-$59.31M

Derivative Transactions0

No derivative transactions reported

Non-Derivative Holdings (Post-Transaction)2

Common Stock

Indirect

Shares owned133.04K

Common Stock

Indirect

Shares owned12.82K

Total

145.87K indirect145.87K

Security Title	Shares Owned	Ownership Type
Common Stock	133.04K	Indirect
Common Stock	12.82K	Indirect
Total	145.87K	145.87K indirect

Derivative Holdings (Post-Transaction)0

No derivative holdings reported