I think it's mostly the uncertainty regarding the situation in Iran and the very clear decision of the IAEA to refer the country to the UN Security Council.

Concern about supply means the risk premium in prices is on the rise. Iran is the major problem, but Nigeria coming on top makes matters worse.

The situation between Russia and Ukraine is a rather (supportive) factor for oil ... as the potential for (gas) supply disruption in Europe is having a correlating effect on other energy commodities including oil.

The IAEA meeting is paramount on investors' minds, because it has the potential to alter the demand supply equilibrium.

Asian central banks have been huge buyers of Treasuries, so if they're going to be buying less to hold down their currencies, then Treasuries will fall.

Prices haven?t fallen by much because of the heavy refinery maintenance seen around March, which still raises some concerns over supply particularly for gasoline.