Oh, so Warren Buffett's been making moves again, and it's all been under the hood because of some SEC exemption. Saw this on Yahoo Finance today. They're speculating he's been dumping billions into something. They're thinking it's Mitsubishi UFJ Financial Group $MUFG 

• Berkshire Hathaway, apparently dropped like $5 billion on some stocks but didn't say which. The thing is, they have to report though if they hit a 5% stake, and that hasn't happened yet. So, this mystery stock's gotta be huge, think $100 billion market cap huge.

• Digging into the filings, there's this $2.38 billion increase in finance-sector holdings, even though they let go of some other finance stocks. Only a handful of financial giants fit the bill, and after some serious Sherlock Holmes work, the list is down to a few.

• Buffett's a smart shopper, only buys if the price feels like a steal. Putting a cap at a P/E of 15 and crossing off names he's already dealt with or isn't interested in, the list gets shorter.

• End of the day, it's between Morgan Stanley and $MUFG . Given Buffett's recent love letter to Japan in his shareholder's letter, betting on $MUFG  isn't a wild guess.

$MUFG 's looking good:

• P/E Ratio: 9
• Market Cap: $121B
• Dividend Yield: 2.4%
• P/S Ratio: 1.6
• Revenue Growth: 9.5%

So, what's the verdict? Buffett's mystery stock $MUFG , or is everyone off track? What's your take? $TSLA $F