The fund industry has grown massively in the last 25 years. It has changed to be a better-run, more professional, and lower-cost business.

Here are some key lessons for investors:

Build a plan and stick to it. Build from the core out. Make sure most of your money and attention goes to core equity and fixed-income funds.

Keep costs low, but evaluate whether some services, like financial or tax advice are worth paying the price for, particularly if you don’t have the time or investing acumen to do it yourself.

Choose funds that are good bets for five years from now because they have depth of managers and analysts, low costs, and strong stewardship to keep them on the right path.

When monitoring your funds, pay more attention to the manager, the analysts, and the fund company behind them rather than changes in performance

Be patient. Even the best managers will underperform in a three-year period. If the management and strategy are still strong, keep the faith.

Do not let the news drive your investments. Markets have priced-in the news probably before you’ve even heard it. Even the smartest investors have difficulty making money by predicting economic trends or choosing which countries will be winners. The relationship between economics and the stock market is not as clear as most people think.

Be open to passive and active investing.

Don’t let the price you paid for an investment drive your decision on whether to sell. It is amazing how many people hold on to a losing investment hoping to get back their loss. If it’s a bad investment, sell and move on. Think instead about returns. If you think one fund will return 5% a year and one in the same category will return 10%, it doesn’t make sense to wait before switching to the 10%.

Invest automatically through a monthly savings plan; the results are great because they enforce a discipline that keeps emotion out of decisions.

Finally, don’t underestimate the importance of costs.