We introduce the <I>Hawkes process with renewal immigration</I> and make its statistical estimation possible with two <I>Expectation Maximization</I> (EM) algorithms. The standard <I>Hawkes process</I> introduces <I>immigrant points</I> via a Poisson process, and each immigrant has a subsequent cluster of associated...</i></i></i></i>

The endo-exo problem lies at the heart of statistical identi fication in many fields of science, and is often plagued by spurious strong-and-long memory due to improper treatment of trends, shocks and shifts in the data. A class of models that has shown to be useful in discerning exogenous and...

The statistical estimate of the branching ratio η of the Hawkes model, when fitted to windows of mid-price changes, has been reported to approach criticality (η = 1) as the fitting window becomes large. In this study -- using price changes from the EUR/USD currency pair traded on the...

We develop a strong diagnostic for bubbles and crashes in bitcoin, by analyzing the coincidence (and its absence) of fundamental and technical indicators. Using a generalized Metcalfe's law based on network properties, a fundamental value is quantified and shown to be heavily exceeded, on at...

Exploiting the near-experimental conditions provided by the British Pound market in US Dollars during the Brexit vote of June 23rd, 2016, we unearth a major challenge to the Efficient Market Hypothesis. With a single factor of prior polling information, we show that the Brexit result could have...