Question 1

How many shares of ACLS does PRIMECAP MANAGEMENT CO/CA/ own?

Accepted Answer

As of 2026-Q2, PRIMECAP MANAGEMENT CO/CA/ holds 610,451 shares of ACLS (AXCELIS TECHNOLOGIES INC).

Question 2

What is PRIMECAP MANAGEMENT CO/CA/'s ACLS position worth?

Accepted Answer

As of 2026-Q2, PRIMECAP MANAGEMENT CO/CA/'s ACLS position is worth $115.6M.

Question 3

Is PRIMECAP MANAGEMENT CO/CA/ buying or selling ACLS?

Accepted Answer

In 2026-Q2, PRIMECAP MANAGEMENT CO/CA/ decreased their ACLS position (-7.3% change in shares).

Question 4

When did PRIMECAP MANAGEMENT CO/CA/ first buy ACLS?

Accepted Answer

Based on available 13F filings, PRIMECAP MANAGEMENT CO/CA/ first reported a position in ACLS in 2024-Q3. They have held the position across 31 quarters.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Decreased	610,451	-7.3%	$115.6M	0.1%	$189.45	0
2026-Q1	Decreased	658,652	-0.9%	$61.3M	0.0%	$85.88	0
2025-Q4	Decreased	664,942	-20.2%	$53.4M	0.0%	$81.55	0
2025-Q3	Decreased	833,676	-2.2%	$81.4M	0.1%	$96.70	0
2025-Q2	Increased	852,296	+2.1%	$59.4M	0.0%	$69.69	30
2025-Q1	Decreased	835,066	-8.9%	$41.5M	0.0%	$49.71	0
2024-Q4	Decreased	916,426	-6.0%	$64M	0.0%	$70.02	0
2024-Q3	Decreased	974,436	-1.6%	$102.2M	0.1%	$107.37	0