Jeff Bezos' Amazon is now worth almost double Wal-Mart's market value — in case investors need yet another reminder of the revolution in retail.

The Seattle-based giant has a market capitalization of over $430 billion, according to FactSet data. In comparison, Wal-Mart's market cap sits below $220 billion as of Wednesday morning.

Like Wal-Mart, Amazon pitches itself to investors as a retailer, but is also a filmmaker, a cloud computing company, a grocery chain and a bookstore, among other things.

So the comparison is, to a degree, apples to oranges — with one company aiming to take people to space and another that's staying focused on keeping its prices low, and not venturing outside the retail sector.

"[Wal-Mart] continues to work to blend physical and digital assets in its operations, including a focus on buy online pick-up in-store, online grocery pickup, and 2-day shipping from its 5 e-commerce fulfillment centers," Guggenheim Securities wrote in a Tuesday note to clients.

"Walmart.com's offering has grown increasingly competitive and the company continues to work on getting its e-commerce inventory levels in the right place to meet its 2-day free shipping promise," the note added.

Some analysts, however, believe Wal-Mart has missed out on opportunities to be as expansive as Amazon, especially when it comes to groceries.

Online grocery shopping could grow five-fold over the next decade, with U.S. consumers spending upwards of $100 billion on food-at-home items by 2025, according an forecast released earlier this year by Food Marketing Institute and Nielsen. AmazonFresh is Bezos' way of capitalizing on this trend.

On Tuesday, BMO Capital Markets issued a new note on Wal-Mart to investors, maintaining its underperform rating on the stock and citing price cuts in grocery and households essentials as pressuring the retailer's top line. Recent pricing data suggest Wal-Mart could have trouble hitting its upcoming quarterly comparable sales growth targets, analyst Wayne Hood said.

As of Tuesday's close, Wal-Mart has climbed nearly 5 percent over the past 12 months, while Amazon has risen close to 55 percent.

Amazon hit an all-time intraday high of $908.54 on Tuesday. Wal-Mart had its last intraday high in January 2015, when the stock peaked at $90.97 per share.