OBERWEIS ASSET MANAGEMENT INC/
"13F equity value" = market value of this filer's US-listed long equity positions only. It excludes cash, bonds, non-US and short positions, so it understates a fund's true assets under management — often by a lot.
13F holdings are disclosed ~45 days after quarter-end, and they never reveal when within the quarter a fund actually bought. So any 13F-based summary is structurally late and blurred — this applies to every fund, including this one.
We backtested copying it. Buying this fund's new positions the day each filing went public, over 32 quarters, returned +4.6% per quarter versus +2.7% from owning every 13F stock, beating that baseline in 56.2% of quarters (excess t = 2.04, statistically significant). Caveat: across all 5,072 funds we tested, past performance shows near-zero persistence (rank correlation −0.018) — with thousands of funds, some will look significant by chance alone.
Quarterly compounding, invested quarters only · entry 47 days after quarter-end (when 13F data becomes public)
Top 20 holdings of 180 · 2026 Q1
| Ticker | Value | Weight | QoQ |
|---|---|---|---|
| AAOI | $199M | | ADD |
| LITE | $187M | | TRIM |
| CRDO | $96M | | ADD |
| DOCN | $80M | | ADD |
| SN | $64M | | ADD |
| NVMI | $60M | | ADD |
| DAN | $54M | | ADD |
| BTSG | $49M | | ADD |
| MTSI | $48M | | ADD |
| RMBS | $45M | | ADD |
| CLH | $41M | | ADD |
| SITM | $41M | | ADD |
| UCTT | $40M | | HOLD |
| ECG | $39M | | ADD |
| FTDR | $38M | | ADD |
| CRS | $37M | | ADD |
| SKYW | $36M | | ADD |
| LSCC | $35M | | ADD |
| GMED | $34M | | ADD |
| CAMT | $34M | | HOLD |
QoQ vs previous quarter's share count · NEW = new position · ADD/TRIM = ±2% shares · HOLD = unchanged.
New positions in 2026 Q1
Method & Limitations
Method: a "new position" = held this quarter, absent last quarter (options excluded; stocks with <50 prior holders excluded to filter spin-off artifacts). Entry 47 days after quarter-end — the first day the public could act on the filing. Benchmark = equal-weighted universe of all 13F-held stocks. Limitations: quarterly snapshots can't see intra-quarter trades; survivorship bias — funds that shut down are absent, which flatters the sample. Statistics, not advice.