XLU is an ETF representing the utility equities and so is typically a defensive play and/or a dividend play. As you can see below, XLU hit a peak at $39 back at beginning of August after an extremely strong run from the lows of $33.5 back in April. As a defensive play, XLU normally is relatively stable so the run to $38 is a bit fast so it was overdue for a drop. It fell to a low of $35.8 a week ago and looks to have formed a short term bottom. Various indicators look like XLU is positioning itself for a rebound (doubly so if the equities market drop back down as it has been for the last few days).
XLU is yielding almost 4% so as a safe play, its a decent one. At worse, you end up with 4% yield...how much are your treasuries again? There is a significant risk in that this drop never took it back down to its recent lows so it was never retested and confirmed as a support point.
Disclaimer: Took a small short term position in XLU as way to hedge a market drop.