The Behavioral Edge®
The study of how investors actually behave versus how they should behave.

What is Behavioral Finance?

Behavioral finance is the study of how psychology influences investor behavior. It starts with the understanding that investors are human. It focuses on explaining why investors often appear to lack self-control, act against their own best interest, and make decisions based on personal biases instead of facts. In short, it assumes that investors are biased.

Traditional Finance

The belief that investors are logical and behave as they should.
vs

Behavioral Finance*

The study of how investors actually behave versus how they should behave.

Investors make mistakes. We look for them.

We’re on the look-out for investor mistakes. There are moments of over-reaction where investors panic. Similarly, there are examples of under-reaction where investors are not paying attention.
There is no certainty any strategy will be successful. The Morningstar Rating for funds, or "star rating", is calculated for managed products (including mutual funds, variable annuity and variable life subaccounts, exchange-traded funds, closed-end funds, and separate accounts) with at least a three-year history. Exchange-traded funds and open-ended mutual funds are considered a single population for comparative purposes. It is calculated based on a Morningstar Risk-Adjusted Return measure that accounts for variation in a managed product's monthly excess performance, placing more emphasis on downward variations and rewarding consistent performance. The Morningstar Rating does not include any adjustment for sales loads. The top 10% of products in each product category receive 5 stars, the next 22.5% receive 4 stars, the next 35% receive 3 stars, the next 22.5% receive 2 stars, and the bottom 10% receive 1 star. The Overall Morningstar Rating for a managed product is derived from a weighted average of the performance figures associated with its three-, five-, and 10-year (if applicable) Morningstar Rating metrics. The weights are: 100% three-year rating for 36-59 months of total returns, 60% five-year rating/40% three-year rating for 60-119 months of total returns, and 50% 10-year rating/30% five-year rating/20% three-year rating for 120 or more months of total returns. While the 10-year overall star rating formula seems to give the most weight to the 10-year period, the most recent three-year period actually has the greatest impact because it is included in all three rating periods. Morningstar rating as of 9/30/25 in the US Fund Small Blend category: Overall: 5 stars; Three-year rating: 5 stars, 568 funds; Five-year rating: 5 stars, 551 funds; Ten-year rating: 5 stars, 408 funds based on risk-adjusted returns. The rating is for the Institutional Share Class (FTHSX) only. Different share classes may have different rankings. The rating is for the Institutional Share Class (FTHSX) only. Different share classes may have different ratings.

*The FullerThaler Behavioral Small-Cap Equity Fund is offered on a limited basis. Please visit https://www.fullerthalerfunds.com/documents to view the prospectus with more details.

Explore our funds

See our Mutual Funds and Separately Managed Accounts.

*Source: DALBAR, Inc. Average investor returns are based on an analysis by DALBAR Inc., which utilizes the net aggregate of mutual fund sales, redemptions and exchanges each month as a measure of investor behavior. Returns are annualized (and total return where applicable) and represent the 20-year period ending 12/31/2015.

The Behavioral Edge® is a registered trademark of Fuller & Thaler Asset Management, Inc.

FullerThaler is a brand name of Fuller & Thaler Asset Management, Inc. This website is directed only to US institutional investors. FullerThaler may only transact its investment advisory business in states where it is notice-filed as an investment adviser or otherwise exempt from state requirements. The information on this website is neither an offer to sell nor a solicitation of an offer to buy any product or service in any jurisdiction where such offer, solicitation, purchase or sale would be unlawful. Nobel Prize® is a trademark of the Nobel Foundation.

© Copyright 2025 FullerThaler. All rights reserved.

chevron-down