|The wealthiest 1 percent of American households own 40 percent of the country's wealth|
If it is owned by the wealthiest 1 percent, it is their wealth, not the country's wealth.
The country's wealth would be all the national forests, government buildings and land, the value of the brand of the US dollar and the United States government, the US military and it's power, the education system, you know, things that are owned by the government of the country. The wealthiest 1% don't own any of those things. The country's wealth is in public assets. On the other hand, Bill Gates' wealth is Bill Gates' wealth.
From 2013, the share of wealth owned by the 1 percent shot up by nearly three percentage points.
My hunch is this jump is just the value of MSFT, AMZN, Berkshire Hathaway and other closely held corporations having their share price go up in value. Most of that share price increase flows into the founder's and majorshareholders pockets, and not into the bank account of the normal Joe. But it doesn't do anything real to life of the founders or to the life of the normal Joe. Amazon at $900 and/or Amazon at $930 doesn't really affect anything meaningful in regard to a "wealth gap", it just scews the measurement to produce articles like the one you are posting.