South Korea's financial authorities will monitor shares of Samsung Electronics Co. to detect possible price-rigging activity amid the recent price swings, market sources said Wednesday.

The move came as the top smartphone maker suffered a 6.18 percent drop in its share price on Friday to 1,427,000 won, the lowest since Feb. 6. It fell for the fourth consecutive trading session on Tuesday to 1,389,000 won.

"We have intensified our oversight on the trading activities related to Samsung Electronics," an official from the main bourse operator Korea Exchange said.

The Financial Supervisory Service also said it will open an official probe on Samsung's shares when it detects suspicious activities on the local stock market linked to price-rigging.

Authorities will also look deeper into transactions of put-options, or the rights to sell shares at a pre-set price in an agreed period, as they benefit most from a decline in share prices.

The daily trading volume of Samsung Electronics' shares jumped nearly four-fold on Friday from the previous trading session to 1.5 trillion won ($1.4 billion).

The plunge came after JP Morgan slashed the target price of the firm's share to 1.9 million won, compared to 2 million won suggested earlier, citing a possible drop in sales of Samsung's flagship Galaxy S4 smartphones.

The market capitalization of the tech giant came to 204.6 trillion won on Tuesday, the lowest since 202.1 trillion won tallied on Jan. 28 this year. Foreigners' foothold in the tech giant came in at 48.8 percent Tuesday, compared to 50.4 percent tallied in January. (Yonhap News)