CNBC Pro dominance of retail industry hits high Inc. employees load boxes with merchandise at the company's fulfillment center in Tracy, California.
David Paul Morris | Bloomberg | Getty Images's share outperformance over traditional retailers has never been greater than it is right now, as evidenced by the "Death by Amazon" index created by Bespoke Investment Group.

The benchmark, which measures the performance of companies most disrupted by the rise of Amazon, has seen its value erode at an accelerated pace this year as shares of the online giant surged more than 90 percent.

It's been a no brainer trade: Buy Amazon and sell Wal-Mart, Macy's and every other brick-and-mortar first store.

But will it keep working or has the Amazon dominance simply gone too far?