Blockbuster deals -- like YouTube’s recent sale to Google for $1.65 billion and Skype’s sale last year to eBay for $2.6 billion -- are giving venture investors new confidence in their ability to cash out said a group of venture capitalists who spoke on a panel at the 2007 Wharton Economic Summit. In addition new sectors like ”clean tech ” an umbrella term for environmentally friendly technologies and trends like the aging of populations in the developed world are creating promising investment opportunities. Even so times remain challenging for many venture capitalists the panelists warned. According to one participant ”15% of the firms have provided [about] 90% of the returns.”