The Yield Curve of the Free Markets ... 10Y-30Y Combination Case.. - US Bonds maturities of 10 Year and 30 Year (long maturities) are mostly influenced by free market participants and not by the FED Funds ... at present time they are not tightening as most combinations based on more short maturities. The indicator in the chart, the combination 10Year-30Years is steepening, sending a different message a possibility of expanding the duration of current economic cycle.