 Online retailer eBay NASDAQ:EBAY saw its stock fall in late July after announcing second-quarter earnings that topped expectations, but included a weak guidance implying that shopping-from-home tailwinds are easing. Thats not good news for EBAY stock.Source: BigTunaOnline Shutterstock.com But its not a deal-breaker, either.Of course, the companys huge growth in the second quarter 22 revenue growth isnt sustainable for this mature e-retail marketplace that normally reports flat growth.InvestorPlace - Stock Market News, Stock Advice Trading TipsBut in the new normal, where e-commerce increasingly becomes ubiquitous, eBays growth trajectory will be permanently higher than where it sat before the novel coronavirus. 10 Gaming Stocks That Will Power Through the New NormalEBAY stock isnt priced for this permanent growth acceleration.Indeed, eBay is still dirt cheap, and is arguably the most attractively valued asset in the e-commerce world.To that end, I say buy the dip in EBAY stock on drops to 50. Solid Q2 NumbersSecond-quarter numbers for eBay were solid. Across the board, growth meaningfully accelerated as buyers and sellers increasingly migrated online amid physical retail closures.eBay added 8 million new buyers in the quarter. Over the previous four quarters, eBay had added just 1 million new buyers.GMV rose 29 year-over-year, versus largely negative GMV growth in previous quarters. Revenues rose 22 year-over-year versus 1 to 3 revenue growth in recent quarters. Sold items rose 24 year-over-year. Operating margins expanded 510 basis points.Overall, it was a solid quarter, but investors were concerned by the outlook.Specifically, for the third quarter, GMV growth is expected to decelerate into the high teens range, while revenue growth is expected to decelerate into the mid-teens range. For the full year, revenues are expected to rise just 13, implying further deceleration in the fourth quarter.In other words, eBay management is saying with its guidance that the Covid-19 tailwind is easing, rapidly, and that itll be all but gone by 2021.This spooked investors and is largely why EBAY stock dropped post-Q2 earnings. A Permanent Growth AccelerationeBay may not report 20 revenue growth ever again, but thats not very important.What is important is that, thanks to the Covid-19 pandemic and various platform improvements, eBays growth trajectory post-2020 will be permanently more robust than it was pre-2020.Covid-19 has accelerated e-commerce adoption globally. Given that the online selling experience is quite robust, with ultra-fast shipping times, ultra-low prices and ultra-seamless browsing capabilities, it is very likely that many of the consumers who have pivoted to online shopping in 2020 will continue to shop online long after the Covid-19 pandemic fades from the scene.Broadly, then, Covid-19 has created a multi-year tailwind for the entire e-commerce space.At the same time, eBay is taking all the right steps to improve its platform, by simplifying the listing flow, enabling sellers with tools like traffic data analytics, and introducing a dark mode on the app.The convergence of these two tailwinds implies that eBays growth trajectory, which was anchored before this year on flat growth with flat margins, will be characterized by mild, low single-digit revenue growth and incremental margin expansion going forward. EBAY Stock Is UndervaluedGiven this permanent growth acceleration and the companys robust exposure to e-commerce, EBAY stock is attractively undervalued today.The stock trades at just 16x forward earnings. Thats about as cheap as it gets in the e-commerce world. The average forward earnings multiple for an internet retail stock today is above 80.On this basis alone that you have an online retail stock trading at 16x forward earnings, EBAY stock is a strong buy on weakness.Even further, EBAY stock is undervalued relative to its own long-term growth potential.On the assumption that eBay can sustain low single-digit revenue growth and mild margin expansion into 2025, I think the company can do about 5 in earnings per share by then.Based on a market-average 17x forward earnings multiple, that implies a 2024 price target for EBAY stock of 85. Discounted back by 8.5 per year, that implies a 2020 price target of over 60.Thus, EBAY stock is both undervalued relative to peers, and its own growth prospects. Bottom Line on EBAY StockYes, the best of the shopping-from-home tailwind is moderating for eBay.But, in the bigger picture, Covid-19 has permanently accelerated this companys growth narrative. Post-2020, eBay should be able to leverage strong e-retail tailwinds and platform improvements to sustain positive revenue and profit growth.Assuming so, then EBAY stock is attractively undervalued today, at just 16x forward earnings. Buying on dips towards 50 seems like the smart move.Luke Lango is a Markets Analyst for InvestorPlace. He has been professionally analyzing stocks for several years, previously working at various hedge funds and currently running his own investment fund in San Diego. A Caltech graduate, Luke has consistently been recognized as one of the best stock pickers in the world by various other analysts and platforms, and has developed a reputation for leveraging his technology background to identify growth stocks that deliver outstanding returns. Luke is also the founder of Fantastic, a social discovery company backed by an LA-based internet venture firm. As of this writing, he did not hold a position in any of the aforementioned securities. More From InvestorPlace Why Everyone Is Investing in 5G All WRONG Americas 1 Stock Picker Reveals His Next 1,000 Winner Revolutionary Tech Behind 5G Rollout Is Being Pioneered By This 1 Company Radical New Battery Could Dismantle Oil Markets The post Buy the Dip in eBay Stock On Drops To 50 appeared first on InvestorPlace. 