After getting pummeled last year, the Energy Select Sector SPDR (NYSEArca: XLE), the largest equity-based energy exchange traded fund, and rival energy ETFs started 2019 in fine form, but last week’s declines spooked some investors.

Though XLE is still up 8.63% year-to-date, the fund is lower by 2.41% over the past week. Data indicate those declines unnerved some investors.

XLE “lost $632 million last week. That marked its largest weekly outflow since July 2017, data compiled by Bloomberg show,” reports Bloomberg.

Departures from XLE came ahead of a massive earnings week for the energy sector. This week, over 55% of the components in XLE’s underlying index report fourth-quarter earnings. That includes the benchmark’s two largest names – Dow components Exxon Mobil Corp. (NYSE: XOM) and Chevron Corp. (NYSE: CVX) – later this week.

All About Oil

“Oil fell below $52 a barrel on Monday after advancing nearly 27% from its Dec. 24 low as OPEC cut production. But news that the U.S. is pumping more has helped reignite supply concerns based on record American output, climbing stockpiles, and uncertainty about whether trade tensions between the U.S. and China will be resolved,” according to Bloomberg.

Last month, the energy sector experienced a short-lived rally after lengthy Organization of the Petroleum Exporting Countries (OPEC) discussions finally came to a conclusion, resulting in a larger-than-expected production cut that sent oil prices higher.