Debunking Investment Myths: A Practical, Evidence-Based Way to Invest
Jan 1, 2026
Endeavor Advisors
Many investors struggle not because markets are broken, but because long-standing myths lead them toward costly decisions. At Endeavor Advisors, we rely on decades of academic research to guide how portfolios are built and managed. Instead of guessing what the market will do next, we focus on what evidence shows actually improves long-term results.
Below, we first address common investment myths, then explain the principles we use to help investors pursue better outcomes for their chosen level of risk.
Common Investment Myths vs. What the Evidence Shows
Myth | What Research Shows |
|---|---|
Investing is basically gambling | Markets are driven by businesses creating value; patient investors are rewarded over time |
You must time the market to succeed | Frequent trading increases costs and lowers returns for most investors |
Skilled professionals consistently beat the market | Very few managers outperform after fees, and it’s nearly impossible to identify them in advance |
Strong past performance predicts future success | Yesterday’s winners often revert back to average performance |
The investment industry often benefits when investors trade frequently, chase performance, or pay high fees. Unfortunately, these behaviors usually work against long-term investors. High costs, taxes, and emotional decisions quietly erode returns, even when markets themselves are doing well.
Rather than relying on predictions or “hot” investment ideas, Endeavor Advisors follows an evidence-based approach grounded in how markets actually work.
We seek to maximize each investor’s return for their chosen level of risk by:
Embracing markets
Diversifying broadly
Controlling expenses
Minimizing taxes
Maintaining discipline

1. Embracing Markets
Embracing markets means accepting that prices already reflect the combined knowledge and expectations of millions of investors around the world. This makes consistently outguessing the market extremely difficult.
Instead of trying to predict short-term movements, we focus on participating in the long-term growth of the global economy.
Markets reward investors for taking risk, not for making predictions
Stocks (ownership in companies) have historically provided higher returns than bonds, but with more ups and downs
Bonds generally offer lower returns but help reduce overall portfolio volatility
Academic research has identified specific risk factors (measurable characteristics like owning stocks instead of bonds) that explain why different investments earn different returns. Understanding these risks helps us design portfolios that align with each investor’s goals, time horizon, and comfort with uncertainty.

2. Diversifying Broadly
Not all risk is rewarded. Putting all your money into a single stock or sector adds unnecessary risk without increasing expected returns.
Diversification simply means spreading investments across many companies, industries, and countries so no single outcome can derail the entire portfolio.
Company-specific risk can be reduced through diversification
Different asset types perform well at different times
Global diversification allows investors to capture returns wherever they occur
A well-diversified portfolio doesn’t eliminate market ups and downs, but it helps smooth results and reduces the impact of any single disappointment.

3. Controlling Expenses
Costs are one of the few investment factors investors can directly control and they matter more than many realize.
In addition to visible fees, like a mutual fund’s expense ratio, investors often pay hidden costs from trading inside funds. Research estimates these transaction costs average about 0.5% per year, on top of stated fees¹.
A total cost of 1.5% may sound small, but it can consume over 20% of long-term returns
Fees compound just like returns, eexcept in the wrong direction
Lower costs increase the portion of market returns investors actually keep
At Endeavor Advisors, we focus on paying for what adds value such as thoughtful portfolio design and disciplined implementation, while avoiding strategies like market timing and stock picking that rarely justify their costs.

4. Minimizing Taxes
Investment returns don’t matter nearly as much as what you keep after taxes. Taxes can quietly reduce wealth over time if they’re not thoughtfully managed.
We take a coordinated approach to tax efficiency, working alongside clients and their CPAs to structure portfolios intelligently.
Using tax-advantaged accounts when appropriate
Placing investments in accounts where they are most tax-efficient
Harvesting losses to offset taxable gains
Favoring tax-efficient funds and municipal bonds when suitable
Tax planning isn’t about avoiding taxes altogether. It’s about reducing unnecessary tax drag so portfolios can compound more effectively.

5. Maintaining Discipline
Emotional decision-making is one of the biggest threats to investor success. Fear during market declines and overconfidence during rallies often lead to buying high and selling low.
This pattern is known as the behavior gap. This is the difference between market returns and what investors actually earn due to poor timing. Studies estimate this gap costs investors roughly 2% per year².
Media headlines amplify fear and excitement
Short-term noise distracts from long-term goals
Emotional decisions increase trading, taxes, and fees
One of our most important roles is helping clients stay disciplined during market volatility. By clearly explaining risks ahead of time and reinforcing the long-term plan, we help investors remain invested and avoid costly reactions.

Key Takeaways
Markets reward patience, diversification, and discipline, not predictions
Broad diversification reduces unnecessary risk without sacrificing expected returns
Costs and taxes quietly erode wealth but can be managed with intention
Emotional decisions are often more damaging than market declines
An evidence-based approach improves the odds of long-term success
At Endeavor Advisors, we believe investing doesn’t need to be complicated to be effective. By focusing on what research shows works and avoiding what doesn’t, we help investors build portfolios designed for real-world success.
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Sources
¹ Bogle, J. C. (2014, January/February). The Arithmetic of ‘All-In’ Investment Expenses. Financial Analysts Journal.
² DALBAR (2012). Quantitative Analysis of Investor Behavior.
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Disclosure: The views expressed herein are exclusively those of Endeavor Advisors, LLC (‘EAL’), and are not meant as investment advice and are subject to change. All charts and graphs are presented for informational and analytical purposes only. No chart or graph is intended to be used as a guide to investing. EA portfolios may contain specific securities that have been mentioned herein. EAL makes no claim as to the suitability of these securities. Past performance is not a guarantee of future performance. Information contained herein is derived from sources we believe to be reliable, however, we do not represent that this information is complete or accurate and it should not be relied upon as such. All opinions expressed herein are subject to change without notice. This information is prepared for general information only. It does not have regard to the specific investment objectives, financial situation and the particular needs of any specific person who may receive this report. You should seek financial advice regarding the appropriateness of investing in any security or investment strategy discussed or recommended in this report and should understand that statements regarding future prospects may not be realized. You should note that security values may fluctuate and that each security’s price or value may rise or fall. Accordingly, investors may receive back less than originally invested. Investing in any security involves certain systematic risks including, but not limited to, market risk, interest-rate risk, inflation risk, and event risk. These risks are in addition to any unsystematic risks associated with particular investment styles or strategies.
