The Portuguese debt office is set to become one of the first big sovereign derivatives users to bow to dealer pressure and agree to two-way collateral postings. The change means the Instituto de Gestão da Tesouraria e do Crédito Público (IGCP) will begin posting assets to its counterparties when the value of a trade swings against it, to mitigate the risk the debt office might default. It also means confronting a series of thorny problems that few of its peers have tackled – most notably