Broadcaster Kim Su-yong reveals best stock trade: down 50%, then five upper-limit hits to +100%

Broadcaster Kim Su-yong, looking back on 26 years of investing, named his most profitable trade as one in which a stock that had fallen 50% hit the daily upper price limit five consecutive times, turning his return to positive 100%.

On Thursday, Kim shared the experience on his YouTube channel "Yukgam Kim Su-yong" in a video titled "I will share all my stock know-how," recounting an investment he made roughly two years ago.

"I had been watching it on my own — nobody tipped me off. The swings were enormous," he said. "So I bought it." He added that the share price kept falling, leaving him wondering whether he had misread the situation. "Before I knew it, I was down 50 percent," he said.

"I thought, 'I knew I shouldn't touch penny stocks,'" Kim said. "Then one day, out of nowhere — upper limit, upper limit again. Five upper-limit hits. Minus 50 became plus 100."

"Every day felt like I was going to die. I must have been out of my mind — why did I buy this stock?" he said, recalling the mental toll the trade took on him.

Kim said the trade in a company he referred to only as "Company H" took place around 2024. He looked up the share price on the day of filming and noted it was 382 won on Friday, adding that the stock was at risk of delisting.

"If you get it right, you make money; if you get it wrong, you just lose everything," he said. "It is genuinely dangerous. I will never do it again." He added that since then he has stopped picking individual stocks and instead invests in index-linked ETFs.

Kim cited "buy in stages, sell in stages" as his core investment principle.

"You should never buy a stock all at once," he said. "If you are going to put in 1 million won, buy 100,000 won worth on Thursday, then 200,000 won worth a few days later — spread it across four or five purchases."

"I sell in stages too. This is the know-how I have built up over many years," he said. He added that when selecting a stock, investors should first pull up a 10-year chart and assess whether the current price is expensive or cheap.

That day, Kim also addressed his trading account, which had drawn attention after being revealed on the Netflix variety show "Gaemi Kim Won-hun: The World of Stocks" — specifically the figure of a cumulative trading volume of 43 billion won.

"If you only read the headline, you would think I am managing 43 billion won," he said. "What is true is that I bought and sold 43 billion won worth of shares in total. For example, if you buy and sell with 100 million won four hundred times, your cumulative trading volume adds up to 40 billion won."

Kim's investing life began with losses. In 1999 he made his first stock purchase with 20 million won ($15,100), only to lose 18 million won within a year. In 2007 he started again with 30 million won, but a stock tip from an acquaintance ended in a delisting that cost him around 50 million won. He began hosting a securities broadcast program in 2011, where he learned to read charts and analyze companies, and reinvested during the COVID-19 market crash, eventually recovering all his past losses.

"I am not an economic expert, so this is just my personal view," Kim said, expressing concern about the recent rally in semiconductor shares. "I think they have risen too much."

He also cautioned against chasing trends. "People who know nothing about stocks are breaking their savings accounts to get into the market," he said. "If someone around you brags about making money, do not think, 'I should do that too.'"

"I recommend long-term investing with money you can afford to lose. Otherwise, do not invest in stocks," he added. "If you check your portfolio every day, it will wear you down mentally."

Large-cap semiconductor stocks have been swinging sharply in recent sessions. The Kospi closed Thursday down 3.52 percent at 5,533.77, giving back in a single session all of the gains of more than 3 percent it had posted on Wednesday. As of 11 a.m. Friday, the Kospi had fallen more than 3 percent in early trading, dropping to the 5,300 level.