This article is full of fail.
First:
There are only 11 million bitcoins in existence, and there can never be more than 21 million, so it’s not a very liquid market. If a way ever emerges to break bitcoins up into even smaller fractions, that might solve the problem, according to traders we spoke to.
Then, an attempt at a correction:
Update: Article has been amended to reflect that bitcoins can already be traded in small fractions, indeed to 0.00000001 BTC (eight decimal places). Nonetheless, even with the ability to break bitcoins into small pieces, there are too few bitcoins in existence for institutional traders to be willing to trade them.
So, 1.1 x 10^15 is not enough units to work with? if that was USD, that would by $1 Quadrillion.
Anyhow, the correct answer was that the Bitcoin market is too small for institutional traders to be bothered with it.