The SSO behaved pretty well and was down about 60%, as you would expect.

FORBES: Why Leveraged ETFs Don't Always Boost Returns

If the SSO had worked, you would expect a 3.6% return.

FORBES: Why Leveraged ETFs Don't Always Boost Returns

An unaware investor would think the SSO should be down 0.5%.

FORBES: Why Leveraged ETFs Don't Always Boost Returns

It uses the same standard protocols (such as OAuth) as its social SSO relatives, but instead of posting meals or books to your feed it sends payment information to shops through a secure channel.

ENGADGET

Among the largest underlying components of SSO, in trading today Accenture plc ( NYSE: ACN) is off about 1%, Advanced Micro Devices, Inc. ( NYSE: AMD) is off about 2.4%, and AES Corp. ( NYSE: AES) is lower by about 0.5%.

FORBES: SSO, ACN, AMD, AES: Large Outflows Detected at ETF