The opening and closing prices are determined by a call auction in major stock exchanges, such as NYSE and Tokyo Stock Exchange. The continuous double auction determines the transactions after the opening and before the closing sessions. Meanwhile, certain stock exchanges can limit the information disclosure of the order book during the call auctions. Assume that there are many informed and uninformed traders, who can trade a single risky stock at call and continuous auctions over multiple periods. Consider the different levels of pre-trade transparency on order book during the call auction (completely closed order book, open order book, and the order book information is disclosed every certain period in the call auction). Suggest the appropriate level of the pre-trade transparency in the call auction, which stabilize both of the call and continuous markets (minimize volatility). Provide an economic story (how the informed and uninformed traders make their order and market choices) and market consequence (mid-quote volatility). Explain how your economic story and market consequence change when all traders do and do not learn the fundamental price of the asset. Note that the market choice is the choice at which auction (call or continuous auction) the traders trade.