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OBERWEIS ASSET MANAGEMENT INC/

Location
LISLE, IL
Portfolio Value
Mid $3,371,799,409
Diversification
Diversified
Filing Date
Global Rank
#690 / 8,232 ▲ 190
Top Industry
Communication Equipment 12.6%
3Y Alpha vs SPY
-1.0%
Period ended 2 months ago
Filed May 15, 2026 · 30d
25 quarters · since Mar 2020

Clone Performance

Jun 2023–Jun 2026 · vs SPY

Hypothetical growth of cloning every reported 13F position and rebalancing on each filing, indexed to the same start.

Cloned portfolio
+72.2%
SPY
+76.3%
Annualised alpha
-1.0%
Max drawdown
−28.1%

Estimate. 13F holdings are quarter-lagged and long-only, so the clone rebalances about 45 days after each period end — when the filing becomes public — and excludes options and short positions. Past performance does not predict future results.

Portfolio Concentration

176 positions · as of Mar 31, 2026 · Δ vs Dec 31, 2025
Top Position
5.9%
+2.1 pts
Top 5
18.5%
+4.7 pts
Top 10
26.1%
+5.1 pts
HHI
144
Jun 2023 → Mar 2026 · range 90 – 174
Diversified+37

Portfolio Trend

25 quarters · across all stocks

Sector Breakdown

As of Mar 31, 2026
Sector % Portfolio Value
Technology 40.0% $1,348,262,065
Industrials 18.5% $622,319,740
Healthcare 18.2% $613,646,922
Consumer Cyclical 12.5% $419,950,562
Financial Services 4.3% $144,332,468
Energy 3.7% $125,545,425
Communication Services 1.4% $47,898,359
Consumer Defensive 1.4% $47,487,278
Unclassified 0.1% $1,834,352
Basic Materials 0.0% $522,238

Last Quarter's Activity

Export CSV
Mar 31, 2026 vs Dec 31, 2025

Added To

Positions the filer increased
25 positions
Ticker Δ Shares Shares Value Open

Trimmed

Positions the filer reduced
19 positions
Ticker Δ Shares Shares Value Open

New Positions

Positions the filer opened this quarter
21 positions
Ticker Shares Value Open

Sold Out

Positions the filer fully exited
19 positions
Ticker Shares Value Open

Portfolio Positions

Export CSV View 13F filing
176 positions · $3,371,799,409 total · as of Mar 31, 2026
Showing 1–50 of 176 positions by value · page 1 of 4
Ticker Company Shares Value (USD) % of Portfolio History