The EU would argue that the manipulation worked since the price didn’t drop to zero.
From the Wall Street Journal:
European lawmakers Tuesday backed changes to revitalize the credibility of the Continent’s flagship climate-change program, but uncertainty over the next step meant the vote failed to provide a hoped-for boost to carbon prices.
The Parliament’s Environment Committee agreed in a vote to approve a delay in auctioning permits to emit 900 million metric tons of carbon dioxide on the Continent’s Emissions Trading System. This delay, known as back-loading, is an effort to reduce an oversupply of emissions allowances that has pushed prices down to a level where experts say they no longer stimulate investment into clean energy.