Question 1

How many shares of MPWR does MASSACHUSETTS FINANCIAL SERVICES CO /MA/ own?

Accepted Answer

As of 2026-Q2, MASSACHUSETTS FINANCIAL SERVICES CO /MA/ holds 442,176 shares of MPWR (MONOLITHIC POWER SYSTEMS INC).

Question 2

What is MASSACHUSETTS FINANCIAL SERVICES CO /MA/'s MPWR position worth?

Accepted Answer

As of 2026-Q2, MASSACHUSETTS FINANCIAL SERVICES CO /MA/'s MPWR position is worth $611.2M.

Question 3

Is MASSACHUSETTS FINANCIAL SERVICES CO /MA/ buying or selling MPWR?

Accepted Answer

In 2026-Q2, MASSACHUSETTS FINANCIAL SERVICES CO /MA/ decreased their MPWR position (-22.1% change in shares).

Question 4

When did MASSACHUSETTS FINANCIAL SERVICES CO /MA/ first buy MPWR?

Accepted Answer

Based on available 13F filings, MASSACHUSETTS FINANCIAL SERVICES CO /MA/ first reported a position in MPWR in 2024-Q3. They have held the position across 30 quarters.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Decreased	442,176	-22.1%	$611.2M	0.2%	$1,382.36	0
2026-Q1	Decreased	567,769	-0.5%	$620.7M	0.2%	$1,074.37	0
2025-Q4	Increased	570,719	+2.5%	$517.3M	0.2%	$922.35	38
2025-Q3	Increased	556,587	+14.7%	$512.4M	0.2%	$883.54	43
2025-Q2	Increased	485,388	+6.1%	$355M	0.1%	$731.94	39
2025-Q1	Decreased	457,551	-6.3%	$265.4M	0.1%	$575.12	0
2024-Q4	Decreased	488,300	-28.0%	$288.9M	0.1%	$597.44	0
2024-Q3	Decreased	678,093	-28.0%	$626.9M	0.2%	$914.24	0