But the big change in the fourth edition, released this month, is a new focus on international stocks, which Siegel says should make up 40 percent of the average individual investors equity holdings. Ive always been in favor of international investing, but now its becoming huge, says Siegel. The U.S. is going to be a much smaller fraction of world equity in the years to come. He expects the U.S. share, now just less than 50 percent, to fall to about 30 percent in ten years. As for currency risk, Siegel says the dollar is deeply undervalued. It could go down another 5 or 10 percent, but thats the bottom.