Definition:
OIH, the Oil Services HOLDRs ETF is a sector ETF that tracks the Oil Services Index (OSX). The stocks in the OSX and OIH are companies in the oil services industry. Currently there are 18 equities in the index and fund, however that is always subject to change.
If you'd like to see more related funds, here is a thorough list of oil ETFs and ETNs...
Or if you are more interested in energy investments, here is a List of Energy ETFs.
