Markets were feeling on edge Thursday as a tech selloff, inflation fears, and the continuing stalemate between the U.S. and Iran weighed on sentiment. The Cboe Volatility Index, a widely followed fear gauge that tracks S&P 500 options contracts and trades under the ticker VIX, climbed 0.3 points to 18.1 in early trading. Yields on U.S. treasuries were also slipping early Tuesday as traders weigh up central banks’ response to renewed inflation fears.