Date Ticker FIRMCOUNT Risk Adjusted Return (γ) Change in Market Risk (β ́) Change in Idiosyncratic Risk (σ2 after – σ2 before) 2/20/1996 FDC 2 -0.006087476 0.02552937 6.32225E-05 5/7/1996 ISLI 2 0.0243426 -1.892630856 -0.002437866 5/7/1996 SUNW 2 -0.007177306 -1.025868233 -0.000912965 5/20/1996 NSCP 6 0.017395648 0.827543911 -0.000930735 5/20/1996 ORCL 6 0.00570959 -1.492743834 -0.000170551 5/20...

We estimate the contribution of Massive Compact Halo Objects (Machos) and their stellar progenitors to the mass density of the Universe. If the Machos that have been detected reside in the Halo of our Galaxy, then a simple extrapolation of the Galactic population (out to 50 kpc) of Machos to cosmic scales gives a cosmic density ρMacho = (1 − 5) × 10 hM Mpc , which in terms of the critical densi...