SBI Holdings' brokerage arm was temporarily banned from some trades related to initial public offerings after Japan’s financial regulator said it manipulated stocks, in the country’s second major trading scandal in recent years.

The Financial Services Agency on Friday instructed the nation’s biggest online broker SBI Securities not to solicit trade orders from clients for shares on the day they list. The curbs are effective through Jan. 18. Officials also required the firm to submit a plan to improve operations by Feb. 13, the regulator said in a statement.

While the ban of less than a week is largely symbolic, it comes at a delicate time for Prime Minister Fumio Kishida’s administration, which is trying harder to persuade Japan’s cash-loving households to invest rather than save in order to help the economy. The country’s stock market has been under scrutiny since local authorities charged SMBC Nikko Securities about two years ago with market rigging.