The theory of the so called Dragon-Kings, esp. by Didier Sornette (ETH Zürich), basically states that financial crises and crashes are predictable (contrary to the theory of black swans).
The following paper gives an overview (see esp. section 5, p. 20f. for predictability):
Dragon-Kings: Mechanisms, Statistical Methods and Empirical Evidence by Didier Sornette, Guy Ouillon
Do you know any software, tools, Excel sheets and/or preferably R code/packages with which the predictability of Dragon-Kings can be tested?