They decided to quit playing chicken and trying to get a few more cents out of SWKS.
I owned WMB for dividend reinvestment and it got a takeover offer from ETE for around $58/share. My wife said take it, but there were rumors of other suitors and WMB said it was not enough. Recently WMB agree to the same takeover at $43/share. Since it was getting some cash and some shares, it has sunk even lower.
A bird in the hand.