What: Considering that master limited partnership Williams Partners (NYSE:WPZ) is a subsidiary of parent company Williams Companies (NYSE:WMB), you would think that the two companies' shares prices would move pretty much in tandem. This certainly wasn't the case last month, though, as shares of Williams Companies shot up 14% on the news that it had received an unsolicited offer for its shares, while Williams Partners stock actually declined, in part because Williams Companies declined the offer.

WMB data by YCharts

So what: While there have been backroom negotiations for several months related to the deal Williams Companies rebuffed, it wasn't until this past month that actual news of the deal surfaced when management said that it had received an offer of $64 per share for Williams, which was a considerable premium to its market price at the time. Despite the fact that Williams declined the buyout option, it was enough to send prices soaring, as management believed that it undervalued the company, especially given its more than $30 billion in organic growth projects. 

The reason that shares of Williams haven't remained at those buyout prices is that investors are less certain that a deal can actually get made -- and there are even fears that the company that made the original offer, Energy Transfer Equity, could start a hostile takeover by buying shares of Williams on the open market. 

Shareholders of Williams Partners were a little less enthralled with the idea that the parent company had decided to say no to the offer. While I can't speak for all Williams Partners unitholders, one reason could be that part of the Energy Transfer offer was contingent on Williams Companies cancelling its plans to acquire the remaining shares of Williams Partners in a deal that was announced back in May. If the parent company was to buy the partnership, unitholders could be on the hook for some decent sized tax bills as those units in the partnership were bought out and transferred to shares of a C-corp. If the company were to accept Energy Transfer's offer, unitholders would continue to own what they already owned and would not incur any tax obligations from the deal.

Now what: There is a lot of speculation going on surrounding the negotiations around Williams Companies. It has asked for offers from other companies that may be interested in acquiring it, most likely in the hopes of pushing up the asking price. While management is tied up in these sorts of negotiations, it may be best to sit on the sidelines until some more concrete plans are put in motion -- otherwise you are buying and selling on a lot of speculation today.