Benjamin Graham (Father of Value Investing) and Warren Buffett have stated, "No one can tell when stock will reach its fair value, but for certain stock price and its value should always be moving in the same trend."
Jitta Line depict the perfect picture of above statement, if the stock trended upward Jitta Line shall be trended upward as well, even if stock price isn't closing the gap between Jitta Line. There are definitely more than a "few" factors that affect Jitta Line. It could be the company announcing its new product, stock buybacks, or merger and acquisition, all these factors could thrust the stock price to be closer or further away from its fair value. No one and "No One" can guarantee a 100% when the price will move close to its fair value. Stock market during a downturn or economic set back could have a slower or no growth in price performance.
It is better to save the effort of trying to predict the market movement, but focus instead on its core value, business performance and fair price.