that's like saying a president can't own stock while in office.
They can't. Or, at least, no other president in American History has until now.
You speak as though you have absolutely no idea what liquidation is or what a conflict of interest is. Allow me to educate you in about the most layman way I can:
Let's say that you have an oil sheik from Dubai come over to the U.S. for a conference on crude oil pricing. Let's say he stays in Trump Hotel, which the Donald still has stock in. Let's then say that the price of oil skyrockets and shoots gasoline prices through the roof. It then comes to light that during his stay, that oil sheik payed about 10,000 times the going rate for his room.
Now then, it wouldn't be too big a leap to suggest at that point that the sheik paid off our President on a crude oil deal to make a ton of money. After all, since he wound up paying Trump by way of dividends and earnings through his stock, that's exactly what happened: the President would profit from a deal that hurt the American people.
That is one example. Let's take it one step further:
Let's say Trump owned stock in a defense contractor. He then goes to war with a nation over very dubious reasons. It then comes to light that the most used unit he's sending to war comes from the very defense contractor he owns stock in.
Yea. That wouldn't look very good either, would it?
These are the reasons that no sitting president has ever carried his businesses and stocks into the White House with him: to avoid even the appearance of conflict of interest.
This is something Trump is simply refusing to do. It's almost as if he fully plans on doing exactly that: promoting himself and his businesses through the White House. That is why everybody on the planet except for the minority that is the Trump fangirls are crying "Foul" over it.
As for your lame article, they invested in Treasury Bonds and Notes. Those are not stocks. Those are issued by the U.S. Government. As such, they only profit if the United States profits. That is not a conflict of interest because he isn't personally profiting if the nation suffers.