Eight trillion euros ($10.7 trillion) - that's the price tag the German daily "Die Welt" put on the economic costs of the global financial crisis. It started on September 15, 2008 when the US investment bank Lehman Brothers filed for bankruptcy. It was the highpoint of the subprime mortgage crisis. A global recession would follow and nations were forced to use taxpayer money to foot the bills for billions in rescue packages and loan guarantees to prevent and even graver economic implosion.

Heads of the world's 20 largest industrialized and emerging countries - the so-called G20 - gathered to create a new system of oversight to ensure no financial instruments would be able to cripple the global economy in such a way again. Many reforms were called for. The common goal was to prevent a bank's failure from leading to the complete collapse of the financial system, and to makie sure taxpayers did not have to end up paying for banks' failed high-risk bets.

How safe are banks?

Now, five years after the Lehman crash, the question remains: is the financial system secure or could it happen again? The answer is usually a variant of "yes, but..." German Bundesbank head Andreas Dombret, for example, said it's still too early to give the economic all clear. Jörg Asmussen, Germany's representative on the European Central Bank's executive board, warned of overestimating the "relative calm" that has currently taken over financial markets.

Yet, much has been achieved. Martin Faust of the Frankfurt School of Finance and Management told DW: "Some steps have certainly been taken. Banks are on more solid footing in terms of capital resources." Some banks, however, are still too big. If such an institution got into trouble, countries - and their taxpayers - would have to get involved in a bailout. "That's where one hasn't been thorough enough. There's the expression 'too big to fail,' and the internationally active big banks should have been scaled down."

Threat of a crisis

Sven Giegold, a globalization critic and Green party member of the European Parliament, said regulation of the financial sector is moving in the right direction by requiring banks to keep more capital on hand, shedding light on the shadowy areas of derivatives and hedge funds. "But the dangers of a crisis have not been averted because high levels of debt have not changed," he told DW. "We are sitting on the same debt bubble, and there are a number of ways it could lead to undesirable developments."

Limits on shadow banking sector

The so-called shadow banking sector, which is estimated to be responsible for trillions of euros worth of investments, will be put on a leash next year. The G20 agreed to a timeline at its September summit in St. Petersburg that will place oversight on hedge funds and other currently unregulated finance institutes. German Chancellor Angela Merkel said the move shows "we are sticking to our word that every financial actor, financial trading location and financial product will be subject to regulation. That's something the world has to work on."

There is still a lot of work to be done, agreed Michael Hüther, director of the Cologne Institute for Economic Research (IW). He said there is "a long development and learning process" but added that leaders were currently on the right track and had sketched out a plan should the crisis rear its head again. "On September 16, the Monday after Lehman's bankruptcy, no one knew what to do," he said. "No one would answer the phone."