Murdoch invested in Theranos ~100M a few years ago https://www.theguardian.com/media/2016/nov/29/rupert-murdoch-theranos-investment-wall-street-journal https://

Murdoch invested in Theranos ~100M a few years ago https://www.theguardian.com/media/2016/nov/29/rupert-murdoch-theranos-investment-wall-street-journal https://www.theguardian.com/media/2016/nov/29/rupert-murdoch... You can only consider the investment "failed" if the company goes belly up. Till then, you have to wait to write the investment off (and request a tax credit on the loss). Selling it is a way to proof your investment is now worth ~zero - so you can write it off in the next fiscal year.