Masayoshi Son, founder and CEO of SoftBank Group, confessed to losing $50 million when he sold his Bitcoin (BTC) back in 2018—because the coin’s volatility was too “distracting.” To this day, he still “doesn’t understand” the crypto, Son noted during The New York Times DealBook conference on Wednesday.

Recalling that time, Son said a friend suggested he should invest 1% of his personal assets in Bitcoin. He ended up doing so in late 2017, an amount that was “about 200 million.” After buying the coins, Son quickly discovered how volatile the price of Bitcoin was and began spending at least five minutes every day looking at its price swings.

In the end, his investment was “distracting [his] own focus on [his] own business,” Son noted, so he sold the coins in early 2018, losing around $50 million in the process—by his own estimation. However, a report by The Wall Street Journal suggested that Son’s loss was closer to $130 million.

“I feel so much better,” Son said about the sale, adding, “I think digital currency will be useful. But I don’t know what digital currency, what structure, and so on.”

According to WSJ, Son bought his BTC in late 2017—during the coin’s historic bull run that culminated in Bitcoin’s all-time high of nearly $20,000. However, since January 2018, the price of BTC gradually went downhill, dropping to around $4,000 in December.

As Decrypt reported, Bitcoin’s market capitalization has recently exceeded that of Mastercard’s amid the crypto’s continuing bull run. According to Assetdash, it now ranks 16th among top assets in the world.

The BTC price rally has kept on gathering steam ever since payment behemoth PayPal first announced that it will allow its customers to buy, sell and hold cryptocurrencies. That and a host of other reasons.