It was a slow start for stocks Tuesday as investors took in a historic move by Japan's central bank and looked ahead to tomorrow's policy announcement from the Federal Reserve. However, a midday reversal from mega-cap chipmaker Nvidia ( NVDA ) helped boost sentiment into the close.  

It's a busy week for global central bank headlines. While tomorrow's statement from the Fed is arguably the most important event on the economic calendar, an overnight decision from the Bank of Japan did not go unnoticed. 

Specifically, the island nation's central bank lifted its short-term interest rates to a range of 0% to 0.1%. This marked the central bank's first rate hike in 17 years and ended a period of negative interest rates that's been in place since 2016.

"Strong wage concessions given to workers by Tokyo's largest labor union pushed the Bank of Japan to raise interest rates," says José Torres, senior economist at Interactive Brokers ( IBKR ). "The central bank had previously focused on deflation, sluggish economic momentum, and an aging population during the past decade and change," but now remains committed to its accommodative stance, Torres adds.

As for tomorrow's conclusion of the Fed's March meeting, it's all but guaranteed that the central bank will keep interest rates unchanged. However, Wall Street will be keen to see the Fed's "dot plot," which summarizes what each member expects monetary policy to be going forward and could signal where the central bank expects the federal funds rate to be at the end of the year.

Nvidia ( NVDA ) swings higher after new AI chip reveal

In single-stock news, Nvidia ( NVDA ) was in focus as the chipmaker hosts its global artificial intelligence (AI) developers conference. Notably, the company unveiled a new line of AI graphics processing units (GPUs), or chips, called "Blackwell." In addition to boosting performance speed, these new chips will lower energy consumption. They will cost around $30,000 to $40,000 apiece, according to Nvidia ( NVDA ) CEO Jensen Huang.

NVDA said it anticipates some of Wall Street's biggest companies – including Amazon.com ( AMZN ) , Alphabet (GOOGL, -0.4%) and Microsoft ( MSFT ) – will use its Blackwell GPUs.

"All told, we view NVDA's announcements as impressive and see its total addressable market expanding at a faster pace than any other major tech company over the next decade," says CFRA Research analyst Angelo Zino (Buy).

The Magnificent 7 stock was down more than 3% to start the day but closed up 1.1%.

Super Micro Computer ( SMCI ) slumps on stock offering news

Elsewhere in the tech space, Super Micro Computer ( SMCI ) plunged 9.0% after the AI server, software and infrastructure company said it will sell 2 million shares of common stock. This will bring the total number of outstanding SMCI shares to 58 million. 

"The principal purposes of this offering are to obtain additional capital to support our operations, including the purchase of inventory and other working capital purposes, manufacturing capacity expansion and increased R&D investments," Super Micro Computer ( SMCI ) said in a regulatory filing.

SMCI is one of the newest members of the S&P 500, having joined the broad-market index on March 18. Even with today's decline, shares have more than tripled on a year-to-date basis. 

As for the main indexes, the Nasdaq Composite rose 0.4% to 16,166, the S&P 500 gained 0.6% to 5,178, and the Dow Jones Industrial Average added 0.8% to 39,110.