A. The Plaintiff is a company that runs an investment trading business, an investment brokerage business, etc. under the Financial Investment Services and Capital Markets Act, and the Defendant is an ordinary investor who, on June 15, 2017, opened an overseas derivatives trading account (the account number C; hereinafter “instant account”) through the Plaintiff and traded overseas derivatives through HTS (the program that allows investors to trade stocks, etc. with cell phones and computers, etc. at home or office, etc.).

B. The Plaintiff’s terms and conditions related to the transaction of overseas derivatives, etc. 1) The Plaintiff’s agreement at the time of opening the instant account and applied to the transaction of overseas derivatives (hereinafter “instant terms and conditions”).

The main contents are as shown in attached Form 1, and the notification of risk of overseas derivatives issued by the Plaintiff to the Defendant at the time of opening the account of this case (hereinafter referred to as “instant notification of risk”).

(ii)The main contents are as shown in Appendix 2. (ii) the total value of the asset assessment in the account for transactions of foreign derivatives is the degree lower than that of the good faith deposit, and the risk is calculated as “[1 ± (value assessed of deposited assets ¡À consignment deposit)”.

C. On February 5, 2018, the Defendant: (a) on February 5, 2018, purchased options owned by the Defendant; and (b) on February 5, 2018, on February 5, 2018, concluded a settlement agreement for a total of 309 items of options (309 items of options) in Japan as of February 5, 2018; (c) on February 6, 2018, due to the rapid increase in the interest rate on the U.S. bonds in the overseas stock market, the Japanese NIKKI index was also droped to a large width.

Accordingly, the risk of the account of this case has rapidly increased, and its risk reached 100% around 09:00:14 on February 6, 2018.

3. On February 6, 2018, at around 09:37, the Plaintiff traded all outstanding settlement agreements held by the Defendant, and the result of liquidation was 437.