The war on cash has been going on for decades. The U.S. abolished the $500 bill in late 1969. (The old $500 bill featured a portrait of President William McKinley, by the way. I remember seeing a few when I was a kid.)

Today's $100 bill is only worth 10 cents on the dollar compared with the $100 bill of 1969.

Europe will abolish the 500 euro this year. We all recall what happened in India in late 2016 when India abolished the 500 and 1,000 rupee notes (worth about $10 and $20, respectively); there was mass chaos as peasants lined up to turn in the old notes for digital credit.

ATMs were shut down because the replacement notes were too big for the ATMs!

Now the war on cash is being taken to a new level. China, the world's most populous country and the world's second-largest economy, has said that physical cash may soon become obsolete.

China has huge digital payments platforms developed by their own companies Tencent and Alibaba, in addition to traditional credit and debit cards and mobile phone payments.

Movements like this might start slowly, but they gain momentum and end quickly. Cash can be expensive to handle because vendors have to hire armored cars to move it, buy machines to count it, pay premiums to insure it and risk losses due to theft.