Piper's Gene Munster Defends Amazon: 'Investors Misinterpreting ChannelAdvisor's Data'

Amazon.com, Inc. (NASDAQ: AMZN) sold off Tuesday as Prime Day was underway. The stock saw a sharp downturn around 1:42 p.m. ET after it was reported ChannelAdvisor said Prime Day sales were flat year over year.

"We believe investors are mis-interpreting ChannelAdvisor's reported data on Prime Day," Piper Jaffray's Gene Munster said in a mid-day note. "ChannelAdvisor has a crystal ball into the sub-segment of Amazon volume it conducts, but we believe it provides a limited read on overall trends."

Related Link: Price Check: Are Amazon's Prime Day Deals Better Than Walmart.com Prices?

The analyst laid out three "core" reasons to support this thesis:

• 1) ChannelAdvisor works with only a subset of Amazon sellers and likely isn't capturing the full extent of brands onboarding for Prime Day 2016.
• 2) ChannelAdvisor reports same-store sales trends and, given Prime Day sellers have more than doubled year-over-year, same-store sales metrics should face headwinds.
• 3) Amazon appears have reorganized the deal flow/structure of Prime Day.

"With Prime Day members up 40-50% y/y since last Prime Day, better press coverage, and much stronger brand/merchant engagement, we believe Prime Day will deliver 37%+ unit growth vs. 2015," the note concluded.

The firm maintained an Overweight rating on the stock.

Shares traded recently at $747.32, down about 0.9 percent or $6.60 per share on the day.