Rep. Ahn Cheol-soo celebrates over his winning the general elections at his Bundang District campaign office in Seongnam, Gyeonggi Province, Thursday. Yonhap

Following the outocome of the general elections on Wednesday, most politician-themed stocks plummeted, except for stocks related to Rep. Ahn Cheol-soo of the People Power Party, according to market watchers, Friday.

Ahn, a physician-turned-computer entrepreneur, won a seat representing Bundang-A constituency in Seongnam, Gyeonggi Province, in one of the fiercest competitions in the elections.

According to the Korea Exchange (KRX), the stock price of AhnLab, the nation's top antivirus vaccine developer founded by Rep. Ahn, ended at 69,200 won ($50.29), a 6.79 percent increase from the previous session. The stock enjoyed an upward trend for two consecutive sessions, following the results of the general elections.

Ahn still holds a 18.57 percent stake, or 1.86 million shares, in AhnLab as its largest shareholder.

Sunny Electronics, formerly led by Song Tae-jong, a former AhnLab employee, also soared by 21.87 percent at Friday's closing, continuing its three consecutive winnings streaks.

However, the positive performances of the two stocks are rather an exception.

Other politically themed stocks have mostly plunged, regardless of whether they are associated with winning or losing candidates, compared to their closing prices on Tuesday, the day before the general elections.

The preferred stock of Daesang Holdings, a theme stock of Han Dong-hoon, the ruling party's interim chairman for the elections who offered to step down recently, fell another 3.22 percent at Friday's closing, continuing the stock's losing streaks for the second consecutive session. Duksung, another politically themed stock related to Han, also fell for two consecutive sessions.

Stock prices of Dongshin Construction and ATEC — associated with Rep. Lee Jae-myung, leader of the main opposition Democratic Party of Korea — also fell, compared to their performances prior to the elections.

Market watchers warn investors of betting money on politically themed stocks, which during election periods often make moves mostly or entirely irrelevant to their corporate fundamentals or values. Also, most politically themed stocks hold tenuous connections to politicians, except in a few rare cases like AhnLab.

"It has been consistenly observed that not only did stocks related to losing candidates, but also those related to winning candidates, experience relative price declines after election days," Nam Gil-nam, senior research fellow at the Korea Capital Market Institute, pointed out after analyzing some 70 politically themed stocks during the 16th to 19th presidential elections.