How to Invest New Cash: Lump Sum vs. Dollar Cost Averaging

An artistic rendering of a stock chart

When you find yourself with new cash to invest and already have a sufficient cash savings buffer, deciding how to deploy that money can feel daunting. Should you invest all at once or spread it out over time? In personal finance, the debate between lump sum investing and dollar cost averaging (DCA) is a common one. Understanding the pros and cons of each approach can help you make a confident decision.

Lump Sum Investing: A Bold and Historically Profitable Move

Lump sum investing means taking your available cash and investing it all at once. For example, if you receive a $50,000 inheritance, you would immediately invest the entire amount into a fund like $VOO, which tracks the S&P 500.

The primary advantage of lump sum investing is that your money is fully exposed to the market sooner, allowing it to benefit from potential growth and compounding over time. Historical data shows that markets tend to rise more often than they fall, with the S&P 500 delivering an average annual return of around 10% over decades.

However, this strategy comes with risk. Investing a large sum just before a market downturn can lead to short-term losses. For emotionally driven investors, watching a substantial investment temporarily decline can be stressful.



Dollar Cost Averaging: A Cautious Yet Effective Approach

Dollar cost averaging involves spreading out your investment over time by investing a fixed amount at regular intervals—for instance, $10,000 per month for five months instead of $50,000 all at once. This method reduces the impact of market volatility, as you’re buying at various price points.

The key advantage of DCA is psychological. It minimizes regret by reducing the likelihood of investing a lump sum at a market peak. This steady approach can also instill discipline, helping new investors avoid the temptation to time the market.

On the downside, dollar cost averaging often underperforms lump sum investing in a rising market. By holding some of your cash on the sidelines, you miss out on potential gains during that period. Over long horizons, the opportunity cost of delayed market participation can add up.

Which Strategy Is Right for You?

Ben Felix talks about lump sum investing vs. dollar cost averaging

The decision between lump sum investing and dollar cost averaging largely depends on your financial situation and personal comfort level. Here are a few factors to consider:

  1. Your Risk Tolerance: If you’re comfortable with short-term volatility and confident in the market’s long-term growth, lump sum investing may be the better choice. If you prefer a more gradual entry into the market, dollar cost averaging might suit you.
  2. Market Conditions: While timing the market is nearly impossible, some investors feel more comfortable dollar cost averaging during periods of high market volatility.
  3. Behavioral Factors: If you’re prone to emotional decision-making, DCA can act as a safeguard, helping you stay consistent and avoid panic-selling during downturns.

A Balanced Perspective

For many investors, the optimal approach is a blend of both strategies. For example, you could invest 50-75% of your cash upfront and dollar cost average the remainder over a set period. This hybrid method captures some immediate market exposure while reducing regret if the market dips shortly after your lump sum investment.

Focus on Your Long-Term Plan

Regardless of the strategy you choose, the most important factor is staying invested for the long term. Whether you opt for lump sum investing, dollar cost averaging, or a combination, investing in $VOO—a low-cost S&P 500 ETF—is a solid choice for building wealth over time. Markets will always have ups and downs, but sticking to a disciplined investment plan ensures you’ll benefit from their long-term upward trajectory.

By evaluating your goals, risk tolerance, and emotional tendencies, you can confidently deploy your new cash and keep your financial journey on track.

Remember, the best investment strategy is the one that aligns with your personal needs and keeps you invested for the future.