Question 1

Does Massachusetts Financial Services own MPWR stock?

Accepted Answer

Yes. As of its Q2 2026 13F, Massachusetts Financial Services holds 442,176 shares of MPWR (Monolithic Power Systems), worth $611.2M.

Question 2

How many shares of MPWR does Massachusetts Financial Services own?

Accepted Answer

As of its Q2 2026 13F, Massachusetts Financial Services holds 442,176 shares of MPWR (Monolithic Power Systems).

Question 3

What is Massachusetts Financial Services' MPWR position worth?

Accepted Answer

As of its Q2 2026 13F, Massachusetts Financial Services' MPWR position is worth $611.2M.

Question 4

Is Massachusetts Financial Services buying or selling MPWR?

Accepted Answer

In Q2 2026, Massachusetts Financial Services reduced its MPWR position by 125,593 shares (-22.1%).

Question 5

When did Massachusetts Financial Services first buy MPWR?

Accepted Answer

Massachusetts Financial Services already held MPWR in its Q1 2019 13F, the earliest on record, and has listed it in 30 quarterly 13F filings.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Decreased	442,176	-22.1%	$611.2M	0.2%	$1,380.32	0
2026-Q1	Decreased	567,769	-0.5%	$620.7M	0.2%	$1,090.07	0
2025-Q4	Increased	570,719	+2.5%	$517.3M	0.2%	$901.84	38
2025-Q3	Increased	556,587	+14.7%	$512.4M	0.2%	$914.50	43
2025-Q2	Increased	485,388	+6.1%	$355M	0.1%	$725.23	39
2025-Q1	Decreased	457,551	-6.3%	$265.4M	0.1%	$573.88	0
2024-Q4	Decreased	488,300	-28.0%	$288.9M	0.1%	$583.90	0
2024-Q3	Decreased	678,093	-28.0%	$626.9M	0.2%	$910.43	0