Turns out that like Libor, Euribor was manipulated

According to a Wall Street Journal article, financial regulators are soon to announce the names of banks that attempted to manipulate Euribor.

Unlike Libor which asked at the question of what rate could the reporting bank borrow at, Euribor asked the question of what rate the reporting bank thought a prime bank could borrow at.

Both of these questions are a substitute for basing these interest rates off of the actual trades that would be used if banks were required to provide ultra transparency and disclose on an ongoing basis their current global asset, liability and off-balance sheet exposure details.

As a substitute, both questions are subject to manipulation.

The manipulation of Euribor is just another reason that it is necessary that banks be required to provide ultra transparency.