It's actually
kinda realistic. The CEO never disclosed their adoptions, making shareholders wonder what else is he hiding and if that reveal will lead to something, anything else.
That rising suspicion will lead to panic selloffs from some general brokers, which kinda makes the 2% drop actually kinda important since that'd mean a LOT of people decided to drop shares, which imo is
kinda unrealistic (aswell) since a 2% drop is a good portion of non-equity firms/non-financial institutions shareholders.
But at the same time realistic since a drop of 10/15% would straight up mean BIG storms ahead, panic selloffs and a death spiral to bankrupcy as people would just keep reacting to the droping prices, creating a vicious cycle of panic selloffs -> dropping prices -> wait-and-see reaction -> panic selloffs.
But back to the reason, really anything affects the stock market. An old CEO talking gibbering during an interview can be seen as untrustworthy leadership and lead to market fluctuations.
Just as hidden adoptees (which, in the grand scheme of things, didn't need to be hidden in the first place but the story would be boring if they knew they were adopted since the start) can lead to suspicion into what else is kept from shareholders.
Which is why the 2% drop is kinda realistic. The big players didn't seem to have sold anything and are most likely waiting on an explanation at the next shareholder meeting. Meaning this reaction is mostly, if not all, from small players, aka people like you and me playing with funny green and red candles, trying to outsmart people with billions as their pocket change, who are more than likely going to do nothing from this reveal since at the end of the day, it's literally just celebrity drama and nothing of consequence to their pockets in the big picture (unless one of the kids is somehow connected to another turbo rich family, which ykw, wouldn't be surprising considering the twists and turns Miyajima can take sometimes).
I'm expecting, if the author decides to point it out later on, for prices to stabilize and come back to their normal levels once big daddy takes the mic to address the issue.
At least that's my amateur take on this.