One benefit of being an active investor for over 30 years is the opportunity to become acquainted with many of the great investors of the past.

One of them — and among the most influential to me as a young investor — was the legendary Martin Zweig.

He passed away over a decade ago. But for more than 40 years, Zweig was one of the titans of American investing.

He began his career in the 1970s as an investment newsletter writer and became one of Wall Street's most successful and influential investors.

His pioneering book, "Winning on Wall Street," originally published in 1970, is one of the most influential books on investing ever written. I highly recommend it!

I recently came across a list of Zweig's investing rules and wanted to share them here with you, along with a few of my thoughts.

Lessons for Winning on Wall Street

As you’ll notice below in the full list, Zweig had 17 rules for investing. Each one is insightful, but a few in particular stuck out to me.

Here are a few of my favorites…

Rule #1: “The trend is your friend, don’t fight the tape.”

This is one of the most popular sayings amongst technicians. It’s also one of the most difficult for new investors to accept.

It feels intellectually “sexier” to buy stocks when they’re down, not when they’re up.

But remember, for a stock to go up 500% or 1,000%, it first has to double, triple, and quadruple. So buy strength and make it your friend.

Rule #3: "If you buy for a reason and that reason is discounted or no longer valid, then sell!"

This is another way of putting my favorite saying, "plan the trade, trade the plan."

I can't emphasize how important it is that if you make a trade and the reason for making the trade changes, you must change along with the trade.

The worst thing you can do as an investor is rationalize a trade that’s now going against you once the situation changes.

Rule #8: “Adapt to change.”

This is related to the point above. But I want to make a bigger point about the “plan” aspect of my favorite saying.

Putting together an investing plan that you know will succeed is essential. I emphasize doing the work and studying great investors like Zweig.

It’s also important that you figure out a plan that fits your particular personality.

Once you do this, you must also accept that the markets change over time, and you need to adapt to those changes.

The most obvious change is when we go from economic growth to a recession.

This almost always results in a bear market, and you will need to adapt your trading plan to remain successful in that new environment.

Rule #11: “Don’t play all the time.”

This is my favorite saying from the entire list. My strongly held view is that you should be doing NOTHING 99% of the time.

Selectivity empowers great trading and investing. Wait for a situation to set up fantastically, and don't force it.

In other words, the most powerful thing you can do as an investor is nothing.

Rule #12: “The market is not efficient but is still tough to beat.”

This is a close second in terms of being my favorite on the list.

Some argue that you can’t beat the market. You and I both know that’s not true.

Beating the market and creating sustainable returns requires not only a great plan but also the discipline to stick with it.

Coming up with that plan and sticking with it both take a lot of hard work. It won’t be easy, but you can beat the market.

If you’re serious about becoming a better investor, start with Zweig’s timeless rules. Then do the hardest part of all: stick to them.