"This chart was put together by Armand Koolen, a Dutch physicist ... In Koolen’s words, the hyperbola fits in with the official gold price in the early 1900s, the revaluation to $35 in 1934, the onset of the secular bull market in 2001, the bottom in October 2008 and its approximate track since then."
At http://financeandeconomics.org/Articles%20archive/2011.12.17%20TMS-hypo.htm