To "big to fail". This is the explanation for a crazy weekend, after a week that saw 2.5 billion euros of Credit Suisse's stock market value disappear.

UBS reached an agreement to buy Credit Suisse for more than three billion euros, an emergency solution between private individuals, but without the approval of the respective shareholders, with the support of liquidity lines and back stops from the public authorities, in order to avoid a liquidity crisis at the beginning of the week and a disorderly bankruptcy.

The agreement between Switzerland's two largest banks was announced at a press conference on Sunday evening and will be quoted at a fraction of Credit Suisse's closing price on Friday. This after a week of turbulence that "wiped" 2.5 billion Swiss francs off the institution's stock market value.

At a press conference, quoted by Eco, late on Sunday, the details of Credit Suisse's takeover by rival Swiss bank UBS were announced, which will end up creating an even bigger bank than the ones that existed. It was the only possible way to avoid bankruptcy without a public bailout.

The Swiss National Bank has agreed to offer a liquidity line of up to 100 billion euros to UBS as part of the deal, they confirmed at the press conference, following the news in the FT. In addition, the Swiss government itself has agreed to provide a guarantee of around nine billion euros to cover potential Credit Suisse credit losses.

According to the information provided at this press conference, Ralph Hamers will be the executive chairman of the combined UBS/Credit Suisse bank, and it was also made clear that there can be no distribution of dividends or allocation of bonuses for the period during which public aid is granted in the form of a liquidity line and a guarantee against possible credit losses.

The deal for UBS to buy Credit Suisse is already drawing international reactions, particularly from the US, the European Central Bank and the UK. The US Secretary of the Treasury, Janet Yellen, said that the US welcomes the deal and guarantees that the American financial system is in a solid position. ECB President Lagarde praised the response of the Swiss authorities and said that the conditions were in place to restore financial stability to the markets.