eprintid: 263 rev_number: 14 eprint_status: archive userid: 27 dir: disk0/00/00/02/63 datestamp: 2011-07-04 09:21:46 lastmod: 2016-04-06 08:02:07 status_changed: 2011-07-04 09:21:46 type: article metadata_visibility: show item_issues_count: 0 creators_name: Podobnik, Boris creators_name: Horvatic, Davor creators_name: Petersen, Alexander M. creators_name: Stanley, H. Eugene creators_id: creators_id: creators_id: alexander.petersen@imtlucca.it creators_id: title: Quantitative relations between risk, return and firm size ispublished: pub subjects: HA subjects: HG subjects: QC divisions: EIC full_text_status: none abstract: We analyze —for a large set of stocks comprising four financial indices— the annual logarithmic growth rate R and the firm size, quantified by the market capitalization MC. For the Nasdaq Composite and the New York Stock Exchange Composite we find that the probability density functions of growth rates are Laplace ones in the broad central region, where the standard deviation σ(R), as a measure of risk, decreases with the MC as a power law σ(R)~(MC)- β. For both the Nasdaq Composite and the S&P 500, we find that the average growth rate langRrang decreases faster than σ(R) with MC, implying that the return-to-risk ratio langRrang/σ(R) also decreases with MC. For the S&P 500, langRrang and langRrang/σ(R) also follow power laws. For a 20-year time horizon, for the Nasdaq Composite we find that σ(R) vs. MC exhibits a functional form called a volatility smile, while for the NYSE Composite, we find power law stability between σ(r) and MC. date: 2009 date_type: published publication: EPL (Europhysics Letters) volume: 85 number: 5 publisher: IOPscience pagerange: 50003 id_number: 10.1209/0295-5075/85/50003 refereed: TRUE issn: 0295-5075 official_url: http://stacks.iop.org/0295-5075/85/i=5/a=50003 citation: Podobnik, Boris and Horvatic, Davor and Petersen, Alexander M. and Stanley, H. Eugene Quantitative relations between risk, return and firm size. EPL (Europhysics Letters), 85 (5). p. 50003. ISSN 0295-5075 (2009)