Muddy Waters yesterday announced a short position in St Jude Medical ( STJ ). The basis for the short is the apparent vulnerability of St Jude's pace makers to cyber attack. Muddy Waters say they have been able to replicate attacks shown to them by cyber security experts. The devices can be made to speed up or power down, the whole ecosystem developed by St Jude has been brought into question. This ecosystem accounts for nearly 50% of St Judes business, they are currently subject to a takeover which makes the short a little riskier than usual, I am short at 77:56. I have followed Muddy waters a number of times (as well as other short sellers) and on the whole done pretty well.