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About US


Oberweis Securities, Inc. (OSI) is a full-service broker-dealer offering a diversified and comprehensive array of quality products and services that can meet our clients’ individual objectives for the future.

At OSI, we help individual investors manage the complexities of establishing and pursuing essential financial goals. Providing clients with high-quality, personalized investment advice has never been more valuable than in today’s ever-changing marketplace, so we offer our clients access to:

  • Premier account asset management
  • Full-service brokerage
  • Online trading

Affiliated Companies

Serving the investment community for more than 20 years, the Oberweis name has become synonymous with quality investment advice. Our network of resources, which continues to evolve with our clients’ changing needs, now includes these affiliated companies:

Oberweis Asset Management, Inc. (OAM)

OAM is an independent investment management firm that invests in high-growth companies around the world. The firm specializes in micro- and small-capitalization growth strategies for institutional investors and for its own proprietary mutual fund family. OAM is headquartered in suburban Chicago with subsidiaries, Oberweis Asset Management (Hong Kong) Limited, and Oberweis Asset Management UK Limited, located in the United Kingdom.

Oberweis Funds

OAM serves as the investment advisor to the Oberweis Funds, a no-load mutual fund family consisting of eight funds. These portfolios allow investors to capitalize on demographic trends, undiscovered growth companies, and unique market opportunities both inside and outside the United States.


  • Global Opportunities Fund (OBEGX) (OBGIX)
  • Emerging Markets Fund (OBEMX) (OIEMX)


  • Micro-Cap Fund (OBMCX) (OMCIX)
  • Small-Cap Opportunities Fund (OBSOX) (OBSIX)


  • International Opportunities Fund (OBIOX) (OBIIX)
  • Focused International Growth (OFIGX)
  • China Opportunities Fund (OBCHX) (OCHIX)

Each of the Oberweis Funds is registered under the Investment Company Act of 1940 as an open-end, diversified management investment company and is qualified for sale in the 50 states.

Investment Process

The Oberweis Aperture

The Oberweis Aperture focuses on investing in small- and mid-cap, emerging-growth stocks. We specialize in shedding light on up-and-coming companies with the potential for increasing profitability and accelerating growth. To identify these companies, we rely on an eight-stage stock selection filter based on key investment traits. Taken together, these eight criteria define the Oberweis Aperture.

The Oberweis Aperture allows us to discern those companies that are experiencing superior growth and have the potential to continue doing so. It also helps us to buy these companies at reasonably attractive prices — valuations that don’t yet fully reflect their earnings potential. The Aperture strategy, in short, deepens our insight and brings sharper focus to our stock selection process.

Also, by helping us to avoid overpaying for stocks with solid growth potential, this approach can help us fine-tune our exposure to better manage the risks associated with investing in smaller-cap stocks.