Samsung SDI (006400.KS) shares surged 27% at the pre-market open on alternative trading system Nextrade (NXT) before sharply reversing course, giving back most of the gains amid heightened volatility. The episode highlights how trades executed during low-liquidity hours can severely distort prices, reigniting concerns over pre-market volatility.
According to Nextrade on Tuesday, Samsung SDI's opening price in the pre-market session was set at 820,000 won, up 175,000 won, or 27.13%, from the previous session's close of 645,000 won. A volatility interruption (VI) was subsequently triggered, temporarily halting trading. When trading resumed, the stock fell rapidly to the 660,000 won range. Buying interest then returned, and the stock is currently trading at 687,000 won, up 42,000 won, or 6.51%, from the previous session's close.
The sharp spike appears to stem from price distortion rooted in the trading structure. Nextrade uses a "continuous trading" system in which buy and sell orders are executed immediately upon matching. In thinly quoted sessions such as the pre-market, even small orders can trigger sharp price swings. In February, Samsung Electronics briefly hit its lower price limit at the open on minimal volume before rebounding to normal levels, sowing confusion among investors.
"The pre-market has limited liquidity, so the stock price reflects execution outcomes rather than true price discovery," a financial investment industry official said. "Given how difficult it is to respond to instantaneous price swings, such surges and plunges are likely to recur."
Nextrade plans to introduce a "static VI" in September as part of system enhancements. Under the mechanism, trading will be halted when prices deviate beyond a certain threshold from the reference price, after which orders will be aggregated over a set period and executed at a single price. By applying single-price auctions when dynamic or static VIs are triggered, the operator aims to strengthen the price discovery function in the pre-market.
