Stock market lessons my son taught me

Joseph Kennedy Sr. had his shoeshine boy. I have my 13-year-old son — and my dad.

Some 92 years ago, Kennedy — father of one U.S. president and two other kids who became senators — is said to have sold off his substantial portfolio in the red-hot stock market after a boy who was cleaning his shoes offered him some stock tips.

The story goes that Kennedy figured that was a signal to sell — everything.

He reasoned that when shoeshine boys were touting shares as sure things, there was a lot of stupid money in the market, propping up prices that were certain to fall.

Kennedy’s move saved him his fortune.

But others who believed the hype lost it all in the Wall Street crash in the fall of 1929.

On Thursday, I thought I saw that shoeshine boy standing in front of me, waving a $10 bill.

My 13-year-old son was excitedly asking for permission to buy a cryptocurrency — dogecoin — which, he yelled, was going to blow up in price by the end of the night, quintupling or more his investment in hours.

“Elon Musk guarantees it!” my son said.

“What?” was my first question.

My second was: “Did you read this in ‘WallStreetBets?’ “

He immediately confirmed that he had been, unknown to me, reading the Reddit group r/WallStreetBets.

That same group in the past week ignited the insane escalation of GameStop‘s share price, costing hedge funds nearly $30 billion in short-sale squeezes.

It’s also led to a flood of commentary about the morality of the stock market, speculation and short-selling, as well as to saber-rattling by lawmakers across the political spectrum, from progressive Rep. Alexandria Ocasio-Cortez, D-N.Y., to conservative Texas GOP Sen. Ted Cruz.

And some r/WallStreetBets users also were touting the virtues of buying dogecoin, with the hopes of riding a similar big wave of price increases.

I laughed at my son.

But he kept pushing me to let him buy some dogecoin. And kept on mentioning Elon Musk.

I had him look at a chart of cryptocurrency price history since 2013, which showed stomach-churning drops that followed bubbles in that investment sector.

“It’s just $10,” he insisted.

I shoved a book in his hand, “Blue Chip Kids,” a basic, but excellent explanation of how markets and financial instruments work. The book’s author, David Bianchi, wrote it after setting out to teach his own 13-year-old son about money.

My own son quickly set that book down on the couch.

I then showed him another book, “Extraordinary Popular Delusions and the Madness of Crowds.”

Since its publication in 1841, Charles Mackay’s account of the Mississippi Scheme, the South Sea Bubble and the Dutch tulip craze has been the gold standard for understanding why financial bubbles happen and how they invariably end very, very, very badly for investors when they pop.

My son didn’t even pretend to read the summary on the book’s back cover.

I’m not surprised.

Kids and adults — particularly adults — are hard to reason with when they are swept up in the…