Foreign investors bought about 140 billion won of Korean shares before the main session opened on Oct. 21, helping lift stocks as Samsung Electronics and SK Hynix increasingly drove gains.
The purchases reversed the direction of the previous morning's early trading, when foreigners sold about 150 billion won. Attention centred on whether buying would continue through the session and into the next day.
Foreign net purchases fell to about 89 billion won after trading began, then recovered above 100 billion won. SK Hynix extended its advance to about 6% as the two chipmakers took a larger role in the market's rise.
The stronger index did not mean every stock recovered its previous losses. Some shares that had fallen sharply a day earlier showed only limited improvement during the rebound.
Aerospace shares showed early strength, followed by suppliers of semiconductor materials and equipment and some biotechnology stocks. Aerospace-related shares continued to attract buying, while Hyundai Motor and Kia traded around unchanged or lower.
Thin quantities of shares available at individual prices allowed prices to rise and retreat quickly after the opening. The swings accompanied the decline in foreign net purchases from their level before the main session.
Foreign purchases on the NXT trading venue initially stood at about 100 billion won before increasing ahead of the opening. Some in the market expected those purchases to support a higher start, with the Kospi expected to open about 100 points higher.
Foreign trading on NXT had often continued in the same direction during the main session, although reversals had also occurred. Whether that pattern would hold remained an open question as foreign purchases fell and then recovered.
U.S. stocks recovered from an initially weaker start as corporate earnings supported trading, oil prices fell and bond yields avoided further increases. Semiconductor shares pared losses, easing concerns about the Korean opening.
Some in the market viewed Samsung Electronics and SK Hynix as attractively priced if anticipated earnings growth materialised. That view depended on future company profits, and the timing of any change in how investors valued the shares remained uncertain.
Attention also centred on whether memory chipmakers would continue their historical pattern of alternating strong profits and downturns. Expectations for earnings formed part of the case for the shares, while foreign purchases remained central to the session's broader strength.
