It appears many investors either ignored or were simply unaware of Nintendo's involvement with Pokemon Go.
Following Pokémon Go's release in the U.S.at the beginning of July, Nintendo's market valuation soared to more than $40 billion, passing Sony.
Prior to the warning, markets had cheered the app's global success as a great sign for Nintendo's long-awaited move into the mobile games market.
Nintendo's meteoric stock jump came to an end last week after the company sent a note to investors informing them about the limited impact Pokemon Go will have on their bottom line.
Nintendo owns 32 percent of The Pokemon Company and is reported to hold a similarly sized stake in Niantic, the US lab that developed the Pokemon Go game.
The drop partially offset Nintendo's recent, extraordinary climb, when its shares and market capitalisation doubled after Pokemon Go's release on July 6. The 32 percent increase in stocks in the previous rally saw a reveral that put Nintendo down in its biggest decline since October 1990.
"The company is not modifying the consolidated financial forecast for now", its statement said.
"The Pokémon Company is [Nintendo's] affiliated company, accounted for by using the equity method", Nintendo said in the filing.
Nintendo has clarified its ownership rights after the US-based company Niantic, the developer of the game, launched the digital monster hunting smartphone app in Japan on Friday. In other words, Nintendo does not believe that the massive interest in playing the Pokemon GO game will make a material difference to its earnings and profits at this time.