Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of National Interstate (NASDAQ:NATL), a specialty property and casualty insurer in the U.S. and Cayman Islands, soared as much as 32% after receiving a tender offer from American Financial Group (NYSE:AFG) subsidiary Great American Insurance Company.

So what: According to the press release from American Financial Group, its subsidiary has offered to purchase National Interstate for $28 in cash per share, without interest, representing a 26% premium above yesterday's closing price. The tender offer is set to expire on March 6, unless the offer is extended beyond that date or terminated early. National Interstate has not made any comments as of yet as to its take on the tender offer.

Now what: Just the simple fact that shares are currently trading at approximately $1 per share above the offer price is an indication from investors that they expect either a competing bid to emerge or for American Financial Group to raise its price. Playing the tender offer game certainly isn't something I recommend, because there's no guarantee a competing bid will emerge or, in this case, that American Financial Group's subsidiary will even keep its bid on the table. Following three hefty quarterly EPS misses in a row, I believe National Interstate shareholders should be fairly content with this offer.

Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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