Explanation:
Let us understand the term "financial market":
Here where the trading places. We talk about shares, debentures, etc.
So when the financial markets are efficient, the market is ready with the information which has been incorporated in to the prices of the product. So with respect to the market value the stock price will change or respond only during the unexpected news and events.
It will not increase or decrease based on the new events. It will not remain constant too all times.