Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

Is the S&P 500 index’s recent rally real, or is it just a bear-market bounce? That’s always a question investors have when the market is rising after a significant selloff. Given all the uncertainty ...

A variation of a puzzle called the “pick-up sticks problem” asks the following question: If I have some number of sticks with random lengths between 0 and 1, what are the chances that no three of ...

Bitcoin BTC $115,271.29 bulls mounted a fresh challenge to a crucial resistance level as traders looked forward to U.S. inflation data. The top cryptocurrency rose to $122,056, testing the 1.618% ...