Commodities have taken a beating for the last couple months, which has accelerated since the start of May. Oil, quoted as WTI, has cratered from a high of $107 per barrel to a low of just under $92 as of yesterday. Since the beginning of May, Brent has done a little better than WTI though and so the spread between the two has increased from $13 back to $17 per barrel.
For some perspective, a long term chart of the spread between WTI and Brent is below. Between this spread and the spread of crude to natural gas, there are some historic anomalies occurring in energy markets currently.