Famed economist Mohamed El-Erian says its a 'real question mark' whether the massive valuations of tech giants like Amazon make 'sense' anymore

· *Famed economist Mohamed El-Erian said in a Thursday interview that he doubts the overall valuation of US tech companies.*
· *While he accepted that their robust balance sheets and positive cash flow will ensure continued outperformance, he said he doesn't know "whether the valuation still makes sense to tell you the...