Much of the marketlooks like it's in a bubble and valuations look stretched, but the worrying behavior has mostly been contained to a handful of individual stocks, not larger indexes. In addition, interest rates remain low, further stimulus is expected and in many cases earnings have held up or been robust, despite the Covid-19 pandemic. Nonetheless, investors are trying to identify what could cause bubbles among individual stocks to pop and whether any of the bursts will spread to the wider market. This week, investors will get fresh data on the manufacturing sector, earnings from Amazon and Google parent Alphabet, and the January employment report. Silver prices rallied to start the trading week, fueled by a wave of fresh enthusiasm from online traders.