Reuters reports that Turkey first started thinking about an FX deposit guarantee scheme in 2018 but decided it was too risky. With the currency in free fall last week, they revived the idea and when it hit 18.00 this week, they launched the unprecedented policy.

So far it's worked, with USD/TRY falling to 12.43 in a dramatic reversal.

The report said officials in Turkey decided that a fall to 18 would damage the lira in ways that were 'hard to repair'.

"If the dollar can fall to around 9, that will be a good level," an unnamed official was quoted as saying. Another said he expects it within a 12-14 range for a couple of months.

This is not your every-day currency chart:

USDTRY daily chart