Credit ratings company Fitch affirmed the BBB+ rating for Nordstrom but downgraded both Macy's and Kohl's. All retained their stable outlook.

Nordstrom was set apart from its retail peers with its recent sales growth as well as sales growth projections. Analyst Monica Aggarwal noted that even though there had been a general slowdown in apparel and accessories sales, with only 2 percent sales growth in 2015, Nordstrom's overall sales grew 7 percent — indicating strong share gains.

The challenge for Nordstrom is that its investments to support online sales growth will put pressure on earnings before interest, taxes, depreciation and amortization, or EBITDA, margins. This is expected to decline to a range of 11 to 11.5 percent from 12.8 percent in 2015.

Nordstrom's growth investments are also expected to limit the free cash flow over the next 24 months.

Macy's and Kohl's both got downgraded from BBB+ to BBB as both suffer from weakness in the mid-market apparel category.