NSH has been slowly rising. I think arbitrage players are accumulating publicly traded GPs, thinking that companies like NSH and ETE will likely be merged with their respective MLPs soon.
I agree with the arbs. NSH could be bought for about .7 units of NS, and with the cancellation of the units owned by NSH and the IDRs, it would only result in dillution of 13%, which would likely be absorbed by the coverage ratio. It would significantly lower the cost of capital and make them competitive with Buckeye and Magellan going forward.
We have seen a wave of GP-MLP mergers (MWP-MWE, BGH-BPL, MGG-MMP, NRGP-NRGY, EPE-EPD as well as MLP-MLP mergers VLI-KSL/KPP, EPD/GTM, WPZ/WMZ, PAA/PPX etc).
I think NuStar will join this group soon. It makes sense that NS and NSH would merger. A tax free all equity exchange could be effected (keep in mind that Greehey isn't likely looking for a taxable event). This would allow NSH holders to get a real nice step up in the distribution while simplifying the capital structure and making themselves more competivie with the MMP's, BPL's of the world.