Before reading Barry Ritholtz’s book How Not to Invest, I wondered if the “Not” in the title was a sign it would be filled with gimmicky ways of giving investment advice.

It isn’t.  Investing well is simple enough, but the world tries to push us towards many types of poor choices that lose us money.  The best advice is a list of the many things to avoid when investing.  This book gives readers the benefit of Ritholtz’s extensive experience with staying on the simple path to investing success.

The book is organized into four parts: Bad Ideas, Bad Numbers, Bad Behavior, and Good Advice.

Bad Ideas

Part of what makes it so easy to push investors toward bad ideas is that we believe secret ways to create wealth exist when, in fact, they don’t exist.  “We don’t like to admit it, but nobody knows anything about the future — not just you and me, but the so-called experts too.”

I’ve had the experience of getting people to agree that the future is unknown, and then they immediately ask what I think will happen with interest rates.  It’s hard to get people to really believe the future is unknown.  Ritholtz does an excellent job of going through some high-profile examples of the futility of forecasters.  Instead of searching for the right seer, he suggests having a “financial plan that is not dependent upon correctly guessing what will happen in the future.”  “Don’t predict what will happen, but rather, assess the range of possible outcomes — what could happen.”

So much of the information we see about investing is just noise.  Ian Cassel said “The maturation of every investor starts with absorbing almost everything and ends with filtering almost everything.”

It is freeing to admit we don’t know what will happen and to plan for a range of possible outcomes.  What too many people do is “Make predictions, then marry those forecasts.”  If they’re wrong, “This usually leads to catastrophic results.”

Bad Numbers

This part of the book starts with a good section on economic innumeracy that discusses denominator blindness, survivorship bias, mathematical models, and the fact that we respond better to anecdotes than data.

Part of what makes this book a pleasure to read is Ritholtz’s optimism.  Paul Volker once said “The only useful thing banks have invented in 20 years is the ATM,” but the author lists 20 useful financial innovations, including index funds, ETFs, low costs, fast trade clearing, and cash-sending apps.  The challenge for investors is to benefit from these innovations rather than lose money with them.

The author sees bull and bear markets as secular periods characterized by either high price-to-earnings (P/E) ratios or low P/E ratios.  I’m not sure how he thinks investors should use this information.  In my case, I use P/E levels to make modest formulaic adjustments to both my asset allocation and my expectations for future stock returns.

Sometimes people overestimate how much the news of the day will affect markets.  Some industries were devastated by Covid-19.  However, it turns out that these industries represent a small fraction of overall markets.  If in “mid-2020, the 30 most economically damaged industry categories were delisted, it would have shaved off just a few percentage points from the S&P 500.”

There is a winner-take-all tendency in many areas, including stocks.  “Just 1.3% of the public companies listed in the United States account for all the market gains during the last three decades.”  We can “find the best-performing stocks by buying them all” in an index fund.

“Simplicity beats complexity every time.  A portfolio of passive low-cost indexes should make up the core of your holdings.  If you want to do something more complicated, you need a compelling reason.”

Bad Behavior

“Bad behavior leads to bad investing outcomes.”  Ritholtz categorizes bad behaviour into ten areas, and he illustrates some of them in an amazing story about a billionaire family called the Belfers.  They lost money with Enron, Madoff, and then FTX!  “Has there ever been a greater, more unholy trifecta than this?”  Even billionaires make some terrible choices.

“If only we made better decisions, we would all be so much better off.”  If we could eliminate all investing mistakes for everyone, we might be better off on average, but there is a zero-sum aspect to investing mistakes.  Your loss is someone else’s gain.  The main overall benefit of eliminating all investing mistakes is that those employed exploiting such mistakes would move on to do something useful for society. Continue Reading…