Yes, 20% in a single stock is generally considered a high-concentration risk by financial planners, placing you in a "caution zone" where a single negative event can significantly damage your overall portfolio. While 5%–10% is often recommended for individual stocks, 20% or more is considered "pushing your luck", demanding active monitoring, high risk tolerance, and a strong, proven investment thesis.
However, you might be taking on too much risk if you hold so much in a higher-risk or less-diversified type of investment. Holding 10% of your total portfolio in a single stock could be too risky.
Warren Buffett emphasizes focusing on a company's intrinsic value over short-term market hype, advocating patience, discipline, and buying wonderful businesses at fair prices, even while acknowledging current high valuations and potential tech bubbles, urging fear when others are greedy and caution with speculative stocks, suggesting that while the market fluctuates wildly, quality businesses eventually align with their true worth, though it takes time.
A widely accepted rule of thumb claims that a properly diversified portfolio must have no more than 10 to 20 percent of total investment assets in a particular stock.
When to take stock profits. When buying a stock, estimate a percentage you plan to sell at. For example, you may sell a position when it profits 20% to 25%. Once you reach this number, sell some or all of the position, or reevaluate your goals.
A bear market is generally considered to be when stocks decline at least 20% from a recent high. US stocks have dipped into bear territory about every 6 years on average over the past 150 years.
Generally, experts recommend investing around 10-20% of your income. But the more realistic answer might be whatever amount you can afford. Investing your money is a tried-and-true way to build long-term financial security and achieve your money goals.
Some organisations may find a 5% ROI acceptable, while others might aim for a higher benchmark, such as 20%, to define a favourable return on investment. What is a good 10-year return on investment? A good 10-year return on investment typically exceeds the average market returns and inflation rate over that period.
The "Rule of 90" in stocks most commonly refers to Warren Buffett's advice for his wife's inheritance: 90% in a low-cost S&P 500 index fund for growth and 10% in short-term government bonds for stability, designed for long-term investors. However, a more pessimistic "Rule of 90-90-90" suggests 90% of new traders lose 90% of their capital within 90 days, highlighting the high failure rate due to lack of education, emotional trading, and poor risk management.
A 2019 study by Harvard Business Review found either Vanguard, BlackRock or State Street is the largest listed owner of 88% of S&P 500 companies. There is a perception that a few select companies own a vast majority of the stock market.
Ramsey Breaks Down the Numbers
“The stock market was up, the S&P in 2023, 26%. The stock market was up in 2024, 25%,” he said on a recent episode of “The Ramsey Show.” “The stock market was up in 2025, 16%. That's a total of 67% in three years.”
50–100 stocks strikes a better balance between expected return and risk. For factor investors, concentration improves returns—owning less stocks has historically improved returns. Seek smart diversification by investing in both value and momentum both in the U.S. and international markets.
How Common Are 20% Declines in the Stock Market? 20% drops in the S&P 500 are still common. Expect one to two within a five-year period. That said, most 20% declines are great long-term buying opportunities because there are relatively a small number of 20% declines that drop beyond 30% (but it does happen).
To make $3,000 a month ($36,000/year) from investments, you need a significant lump sum or consistent, high-yield income streams, with estimates ranging from roughly $300,000 at a 12% yield to over $700,000 for stable Dividend Aristocrats, depending on your investment type, dividend yield, risk tolerance, and strategy. A simple formula is: Investment Needed = ($3,000 x 12) / Annual Dividend Yield.
While there is no one right answer to the question how many stocks should I own?, a diversified portfolio makes sense for many investors. Diversification helps provide the possibility of mitigating risk by spreading out portfolio holdings across different assets, or different types of a single asset.
The general definition of a market correction is a market decline that is more than 10%, but less than 20%. A bear market is usually defined as a decline of 20% or greater. The market is represented by the S&P 500 index. Past performance is no guarantee of future results.