2026 Q1 Portfolio Activity
In 2026 Q1, OBERWEIS ASSET MANAGEMENT INC/ maintained a portfolio of 199 distinct positions. The most significant new addition was Leonardo DRS, Inc., now representing 0.59% of the total fund value. They heavily accumulated shares in Applied Optoelectronics Inc., increasing the position by 15.2%. The fund also reduced its exposure to Ambarella, Inc. by 52.2%.
Position History
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Total Positions
199
Quarter
2026 Q1
Top Holding
AAOI (5.9%)
Top 10 Concentration
26.0%
Turnover Rate
23.4%
Sector HHI
0.18
Items per page:
Showing 1-50 of 199
OBERWEIS ASSET MANAGEMENT INC/ Full Holdings List — 2026 Q1
| Stock | History | Sector / Type | Port % | Prev % | Rank / Prev | Conviction | Change | % Change | Influence | Shares | Mkt Value | Avg Cost | Price Held | 1st Owned | Source | Source Date | Date Reported | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
AAOI
Applied Optoele...
|
Technology | 5.87% | 2.60% |
#1
2
Prev: #3
|
6.3 |
—
|
310,328 | 15.2% |
P
S
|
2,349,969 | $198,783,878 | 2016 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
LITE
Lumentum Hldgs,...
|
Technology | 5.53% | 3.79% |
#2
1
Prev: #1
|
4.2 |
—
|
-14,708 | -5.2% |
P
S
|
266,222 | $187,090,173 | 2017 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CRDO
Credo Technolog...
|
Technology | 2.83% | 3.55% |
#3
1
Prev: #2
|
5.1 |
—
|
346,580 | 51.3% |
P
S
|
1,021,968 | $95,932,136 | 2024 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
DOCN
DigitalOcean Ho...
|
Technology | 2.35% | 1.37% |
#4
6
Prev: #10
|
3.4 |
—
|
148,675 | 19.1% |
P
S
|
927,505 | $79,561,379 | 2024 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
SN
SharkNinja, Inc...
|
Consumer Cyclical | 1.88% | 2.15% |
#5
1
Prev: #4
|
3.3 |
—
|
73,660 | 14.0% |
P
S
|
599,970 | $63,536,823 | 2014 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
NVMI
Nova Ltd.
|
Technology | 1.77% | 1.36% |
#6
5
Prev: #11
|
3.2 |
—
|
24,670 | 21.8% |
P
S
|
137,955 | $59,911,097 | 2009 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
DAN
Dana Inc.
|
Consumer Cyclical | 1.60% | 0.69% |
#7
48
Prev: #55
|
3.6 |
—
|
815,000 | 102.3% |
P
S
|
1,611,500 | $54,226,975 | 2018 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
BTSG
BrightSpring He...
|
Healthcare | 1.46% | 1.24% |
#8
5
Prev: #13
|
3.1 |
—
|
250,970 | 27.6% |
P
S
|
1,158,970 | $49,383,712 | 2025 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
MTSI
Macom Technolog...
|
Technology | 1.42% | 1.12% |
#9
5
Prev: #14
|
3.1 |
—
|
36,926 | 20.6% |
P
S
|
215,886 | $47,941,804 | 2020 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
RMBS
Rambus, Inc
|
Technology | 1.34% | 1.55% |
#10
4
Prev: #6
|
2.5 |
—
|
64,216 | 13.9% |
P
S
|
526,316 | $45,278,965 | 2024 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CLH
Clean Harbors, ...
|
Industrials | 1.22% | 1.00% |
#11
10
Prev: #21
|
3.0 |
—
|
27,485 | 23.5% |
P
S
|
144,355 | $41,390,909 | 2019 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
SITM
SiTime Corporat...
|
Technology | 1.22% | 1.37% |
#12
3
Prev: #9
|
2.5 |
—
|
12,885 | 12.1% |
P
S
|
119,281 | $41,193,693 | 2023 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
UCTT
Ultra Clean Hol...
|
Technology | 1.18% | 0.58% |
#13
51
Prev: #64
|
1.0 |
—
|
11,976 | 1.9% |
P
S
|
640,476 | $39,824,798 | 2010 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ECG
Everus Construc...
|
Industrials | 1.14% | 0.81% |
#14
27
Prev: #41
|
3.0 |
—
|
66,733 | 25.7% |
P
S
|
326,533 | $38,550,486 | 2025 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
FTDR
Frontdoor, Inc.
|
Consumer Cyclical | 1.12% | 1.29% |
#15
3
Prev: #12
|
2.4 |
—
|
107,100 | 17.5% |
P
S
|
717,960 | $37,951,366 | 2023 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CRS
Carpenter Techn...
|
Industrials | 1.10% | 0.95% |
#16
6
Prev: #22
|
2.4 |
—
|
11,822 | 14.3% |
P
S
|
94,433 | $37,220,897 | 2017 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
SKYW
Skywest Inc
|
Industrials | 1.06% | 1.40% |
#17
10
Prev: #7
|
0.9 |
—
|
10,279 | 2.7% |
P
S
|
392,499 | $36,043,183 | 2015 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
LSCC
Lattice Semicon...
|
Technology | 1.03% | 0.85% |
#18
21
Prev: #39
|
2.4 |
—
|
59,800 | 19.0% |
P
S
|
374,436 | $34,732,683 | 2014 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
GMED
Globus Medical,...
|
Healthcare | 1.00% | 0.86% |
#19
16
Prev: #35
|
2.9 |
—
|
122,200 | 45.3% |
P
S
|
392,200 | $33,791,952 | 2015 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CAMT
Camtek, Ltd.
|
Technology | 1.00% | 0.85% |
#20
18
Prev: #38
|
0.9 |
—
|
3,900 | 1.8% |
P
S
|
222,780 | $33,775,676 | 2018 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ARQT
Arcutis Biother...
|
Healthcare | 0.95% | 0.86% |
#21
16
Prev: #37
|
3.4 |
—
|
557,541 | 69.0% |
P
S
|
1,365,941 | $32,181,570 | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
FLS
Flowserve Corpo...
|
Industrials | 0.94% | 1.04% |
#22
5
Prev: #17
|
2.4 |
—
|
24,740 | 6.0% |
P
S
|
434,681 | $31,953,415 | 2023 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
SIMO
Silicon Motion ...
|
Technology | 0.94% | 0.80% |
#23
19
Prev: #42
|
2.4 |
—
|
46,250 | 19.6% |
P
S
|
282,550 | $31,727,540 | 2005 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
LTH
Life Time Holdi...
|
Consumer Cyclical | 0.92% | 1.03% |
#24
6
Prev: #18
|
2.4 |
—
|
101,200 | 9.6% |
P
S
|
1,160,500 | $31,263,870 | 2025 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
RSI
Rush Street Int...
|
Consumer Cyclical | 0.92% | 1.00% |
#25
5
Prev: #20
|
0.9 |
—
|
22,850 | 1.6% |
P
S
|
1,434,560 | $31,201,680 | 2024 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
FCFS
FirstCash Holdi...
|
Financial Services | 0.92% | 0.77% |
#26
22
Prev: #48
|
2.9 |
—
|
34,365 | 26.2% |
P
S
|
165,665 | $31,145,020 | 2022 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
FSLY
Fastly, Inc.
|
Technology | 0.92% | 0.26% |
#27
109
Prev: #136
|
3.4 |
—
|
381,222 | 55.3% |
P
S
|
1,071,022 | $31,123,899 | 2023 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
TPC
Tutor Perini Co...
|
Industrials | 0.90% | 0.95% |
#28
5
Prev: #23
|
0.9 |
—
|
6,700 | 1.7% |
P
S
|
393,900 | $30,405,141 | 2025 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
BROS
Dutch Bros., In...
|
Consumer Cyclical | 0.90% | 0.91% |
#29
1
Prev: #28
|
2.9 |
—
|
193,993 | 48.0% |
P
S
|
598,493 | $30,319,655 | 2024 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
SEI
Solaris Energy ...
|
Energy | 0.89% | 0.62% |
#30
32
Prev: #62
|
2.9 |
—
|
164,989 | 45.0% |
P
S
|
531,889 | $30,057,047 | 2018 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
MMSI
Merit Medical S...
|
Healthcare | 0.86% | 0.87% |
#31
3
Prev: #34
|
3.3 |
—
|
155,449 | 57.8% |
P
S
|
424,209 | $29,240,726 | 2014 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
FSS
Federal Signal ...
|
Industrials | 0.85% | 0.66% |
#32
25
Prev: #57
|
3.3 |
—
|
101,134 | 60.7% |
P
S
|
267,634 | $28,941,941 | 2017 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
AMSC
American Superc...
|
Industrials | 0.85% | 0.88% |
#33
1
Prev: #32
|
0.8 |
—
|
14,000 | 1.7% |
P
S
|
849,900 | $28,769,115 | 2009 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
MRCY
Mercury Systems...
|
Industrials | 0.84% | 1.11% |
#34
18
Prev: #16
|
0.8 |
—
|
-23,017 | -5.6% |
P
S
|
391,023 | $28,509,487 | 1999 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ACA
Arcosa, Inc.
|
Industrials | 0.84% | 0.86% |
#35
1
Prev: #36
|
2.8 |
—
|
46,100 | 20.8% |
P
S
|
267,700 | $28,413,678 | 2019 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
OSIS
Osi Systems, In...
|
Technology | 0.84% | 0.95% |
#36
12
Prev: #24
|
2.3 |
—
|
5,193 | 5.1% |
P
S
|
106,593 | $28,301,507 | 2003 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CNR
Core Natural Re...
|
Energy | 0.83% | 0.58% |
#37
29
Prev: #66
|
3.3 |
—
|
91,400 | 51.2% |
P
S
|
269,800 | $28,256,154 | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
WAY
Waystar Holding...
|
Healthcare | 0.83% | 1.01% |
#38
19
Prev: #19
|
2.8 |
—
|
326,874 | 38.9% |
P
S
|
1,167,474 | $28,147,798 | 2024 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
EHC
Encompass Healt...
|
Healthcare | 0.83% | 1.39% |
#39
31
Prev: #8
|
0.8 |
—
|
-69,486 | -19.4% |
P
S
|
289,485 | $28,001,892 | 2023 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
VCYT
Veracyte, Inc.
|
Healthcare | 0.80% | 1.12% |
#40
25
Prev: #15
|
2.3 |
—
|
113,094 | 15.6% |
P
S
|
839,834 | $27,051,053 | 2018 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
AIR
AAR Corp.
|
Industrials | 0.79% | 0.83% |
#41
1
Prev: #40
|
0.8 |
—
|
-27,575 | -10.1% |
P
S
|
245,125 | $26,831,383 | 2006 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ICUI
ICU Medical, In...
|
Healthcare | 0.78% | 0.88% |
#42
9
Prev: #33
|
2.8 |
—
|
35,670 | 21.2% |
P
S
|
203,710 | $26,309,147 | 2024 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
LFUS
Littelfuse, Inc...
|
Technology | 0.72% | 0.58% |
#43
24
Prev: #67
|
2.3 |
—
|
9,500 | 15.2% |
P
S
|
71,800 | $24,365,330 | 2023 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
PRIM
Primoris Servic...
|
Industrials | 0.70% | 0.74% |
#44
6
Prev: #50
|
0.8 |
—
|
2,800 | 1.7% |
P
S
|
166,100 | $23,758,944 | 2023 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
RELY
Remitly Global,...
|
Technology | 0.67% | 0.51% |
#45
33
Prev: #78
|
2.8 |
—
|
451,500 | 45.0% |
P
S
|
1,454,300 | $22,788,881 | 2025 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
G
Genpact Ltd.
|
Technology | 0.67% | 0.89% |
#46
17
Prev: #29
|
2.3 |
—
|
85,230 | 16.3% |
P
S
|
606,832 | $22,604,496 | 2024 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
AIZ
Assurant, Inc.
|
Financial Services | 0.66% | 0.73% |
#47
5
Prev: #52
|
2.8 |
—
|
19,300 | 23.3% |
P
S
|
102,300 | $22,281,963 | 2023 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
BLBD
Blue Bird Corpo...
|
Industrials | 0.65% | 0.66% |
#48
10
Prev: #58
|
0.8 |
—
|
6,600 | 1.7% |
P
S
|
389,238 | $22,104,826 | 2023 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
IMAX
Imax Corp.
|
Communication Services | 0.65% | 0.88% |
#49
18
Prev: #31
|
0.8 |
—
|
-75,161 | -11.5% |
P
S
|
577,139 | $21,937,053 | 2009 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
LEVI
Levi Strauss & ...
|
Consumer Cyclical | 0.64% | 0.75% |
#50
1
Prev: #49
|
2.3 |
—
|
173,400 | 17.4% |
P
S
|
1,167,300 | $21,583,377 | 2025 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 |
Showing 1-50 of 199 holdings