Sure. It also depends on the point in time and the asset. If the market has just crashed down 30%, I would probably be comfortable making an investment using si

Sure. It also depends on the point in time and the asset. If the market has just crashed down 30%, I would probably be comfortable making an investment using significant debt in certain individual shares if the interest rate is low. At the moment? not so much. Also, say you can acquire a plot of land you want to hold for a long time, and you can acquire it with 10% cash down + pay < 1% annual interest on a secured loan, you'd be an idiot not to take on the debt. Take the remaining cash and invest it somewhere with a higher yield. It depends, is probably the correct answer here. :)