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.

Image source: Windstream.

What: Shares of specialist telecom company Windstream Holdings (NASDAQ:WIN) closed Friday's trading session at $7.83. On Monday, the stock opened at $11.90 per share for a quick 52% weekend surge. Then it fell 17% in short order before settling down in the neighborhood of $10.20 per share. What's going on with this crazy roller coaster?

So what: Actually, that's only part of the Windstream story today. On Friday night, the company spun off its networking hardware assets under a brand-new ticker. Communications Sales & Leasing (NASDAQ:CSAL), as that real estate investment trust is known, has wobbled between $26.60 and $29.50 per share this morning. As of 11:15 a.m., CS&L carried a $4.3 billion market cap while the remaining Windstream ticker was worth $1.1 billion. The two companies add up to about $5.4 billion in total market value, up from $4.7 billion on Friday night. All things considered, it's probably best to mark it up as a 15% price surge for existing Windstream investors.

Image source: Communications Sales & Leasing.

Now what: Windstream's REIT split was a long-awaited move with well-known implications. New Windstream investors can now choose whether to buy into the company's dividend-heavy networking assets under the CS&L ticker, or to look for more growth and smaller dividends in the regular old Windstream ticker. As a reminder, CS&L expects to pay out $2.40 in annual dividends this year, which works out to an 8.4% effective yield at current prices. Windstream's expected payout of $0.60 per share amounts to a lower 5.7% yield. You should expect Windstream to fall out of the S&P 500 market index in the next rebalancing of that index, perhaps to be replaced by the larger market heft of CS&L.