Mike Santoli’s market notes: Tesla’s bad week after bitcoin buy, Never short a dull market?

Mike Santoli’s market notes: Tesla’s bad week after bitcoin buy, Never short a dull market?

This is the daily notebook of Mike Santoli, CNBC's senior markets commentator, with ideas about trends, stocks and market statistics.Is the "never short a dull market" rule of thumb in force? After a six-day win streak the market got no more than three straight dull, flat sessions. Shows a steady bid, even if it's tiring.A lot of broad-market stuff has the look of a rally culminating in the short term – investor positioning pretty extended again, February options expiration next week a plausible exhaustion moment for this phase of the climb, earnings mostly in the books.This BofA gauge has been resolutely supportive of further upside for months even as others have been saying the market was euphoric/overheated. It's now verging on a contrarian Sell signal, given aggressive inflows and extreme risk positioning across markets.It so happens the 4000 mark on the S&P 500 (+2% from here) lines up with some timing/cycle/valuation stuff that could make it tough to surmount and stay above.But the market tone itself is hard to quibble with right now. Leadership Friday by both semis and banks. Treasury yields resuming their uptrend, oil padding its gains, yield curve steeper - supporting the upbeat cyclical story and lifting