May 2, 2003 — The Oberweis Funds:Micro-Cap Portfolio (OBMCX) will close to new investors and most shareholders at the end of this month in an effort to keep from getting too big to be manageable.

The fund, which has seen its assets increase to about $62 million from $25.9 million at the end March, will continue to accept investments only from investors who own shares in certain retirement accounts, such as individual retirement accounts, or in 401(k) plans.

“To ensure that we can continue to take meaningful positions in our most promising micro-cap ideas, we are proactively closing the fund to limit the influx of new investors,” James D. Oberweis, the chairman of Oberweis Asset Management, the fund’s investment advisor, said on the firm’s web site.

The fund, which Oberweis runs with his son, James W. Oberweis, returned 6.5% this year through March, while its peer small-cap growth funds lost 3.8%. Oberweis Micro-Cap was up an average annualized 3.0% for the five years ended in March, compared to a loss of 5.4% by similar funds.

The portfolio carries a 3-Star rank from Standard & Poor’s.