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XLeratorDB/financial Documentation

SQL Server downside deviation of asset returns


DownsideDeviation

Updated: 31 January 2016


Use the aggregate function DownsideDeviation to calculate the downside deviation of asset returns. The formula for DownsideDeviation is:
Downside Deviation formula 
Where

R
=
asset return
MAR
=
minimum acceptable return
n
=
either the number of rows in the GROUP or the number of rows where R < MAR

Syntax
SELECT [wct].[DownsideDeviation](
  <@R, float,>
 ,<@MAR, float,>
 ,<@Full, bit,>)
Arguments
@R
the asset return for a period; the percentage return in floating point format (i.e. 10% = 0.10). @R is an expression of type float or of a type that can be implicitly converted to float.
@MAR
the minimum acceptable return in floating point format (i.e. 10% = 0.10). @MAR is an expression of type float or of a type that can be implicitly converted to float.
@Full
a bit value which determines the treatment of n in the DownsideDeviation equation. When @Full is TRUE then n is the number of non-null rows in the GROUP; when @Full is FALSE then n is the number of rows where @R < @MAR.
Return Type
float
Remarks
·         If @R IS NULL it is not included in the calculation.
·         If @MAR IS NULL it is not included in the calculation.
·         If there are no non-NULL rows in a GROUP then NULL is returned.
·         @MAR must be the same for all values in a GROUP.
·         Available in XLeratorDB / financial 2008 only
Examples
In this example we have returns for an asset and its benchmark for the last three years. The minimum acceptable return is 0.005.
SELECT
   wct.DownsideDeviation(Ra,0.005,'True') as [DownsideDeviation True],
   wct.DownsideDeviation(Ra,0.005,'False') as [DownsideDeviation False]
FROM (VALUES
    ('2012-12-31',0.001378,-0.003929)
   ,('2013-01-31',0.028677,-0.001701)
   ,('2013-02-28',0.005801,0.003165)
   ,('2013-03-31',0.01442,-0.006487)
   ,('2013-04-30',0.00229,-0.004653)
   ,('2013-05-31',0.014905,0.009577)
   ,('2013-06-30',0.008594,0.00588)
   ,('2013-07-31',0.011531,0.005089)
   ,('2013-08-31',0.008268,0.005233)
   ,('2013-09-30',0.013993,-0.004338)
   ,('2013-10-31',0.009147,-0.006109)
   ,('2013-11-30',-0.00316,-0.002222)
   ,('2013-12-31',-0.00595,0.005451)
   ,('2014-01-31',0.013398,-0.008099)
   ,('2014-02-28',0.002847,-0.000299)
   ,('2014-03-31',-0.009544,-0.009809)
   ,('2014-04-30',0.002516,0.008875)
   ,('2014-05-31',0.004626,-0.002681)
   ,('2014-06-30',-0.002141,0.000312)
   ,('2014-07-31',0.009247,0.00936)
   ,('2014-08-31',-0.01253,0.005434)
   ,('2014-09-30',0.00441,0.008157)
   ,('2014-10-31',0.01626,-0.006766)
   ,('2014-11-30',0.013207,0.005742)
   ,('2014-12-31',-0.008561,-0.005063)
   ,('2015-01-31',0.012357,0.004357)
   ,('2015-02-28',-0.002057,-0.00044)
   ,('2015-03-31',0.008217,-0.004866)
   ,('2015-04-30',-0.013439,-0.007649)
   ,('2015-05-31',0.004391,-0.002073)
   ,('2015-06-30',-0.008997,0.00399)
   ,('2015-07-31',-0.001878,-0.00613)
   ,('2015-08-31',-0.014381,-0.00351)
   ,('2015-09-30',-0.001885,0.001172)
   ,('2015-10-31',-0.001121,-0.000024)
   ,('2015-11-30',0.000816,0.002596)
   ,('2015-12-31',-0.003088,-0.009025)
   )n(dt,Ra,Rb)

This produces the following result.


In this example we have 6 managers plus a benchmark stored in the #managers table which is in 'spreadsheet' format. The minimum acceptable rate is 0.005.
SELECT
   *
INTO
   #managers
FROM (VALUES
    ('2012-12-31',-0.002546,NULL,NULL,0.003006,NULL,0.005007,-0.001839)
   ,('2013-01-31',0.00977,NULL,NULL,0.001,NULL,-0.007579,0.008614)
   ,('2013-02-28',0.024726,NULL,NULL,0.005703,NULL,0.006496,-0.004624)
   ,('2013-03-31',0.000942,NULL,NULL,0.007578,NULL,0.008333,0.005031)
   ,('2013-04-30',0.022139,NULL,NULL,0.007118,NULL,-0.007312,-0.005431)
   ,('2013-05-31',0.019449,NULL,NULL,0.005659,NULL,-0.003902,-0.001878)
   ,('2013-06-30',-0.007964,NULL,NULL,0.003757,NULL,-0.001899,-0.00706)
   ,('2013-07-31',-0.008262,-0.002824,NULL,0.003762,NULL,-0.007347,-0.001982)
   ,('2013-08-31',0.009617,0.007319,NULL,0.0022,NULL,-0.002116,0.003867)
   ,('2013-09-30',-0.004118,0.004128,NULL,0.001394,NULL,0.008333,0.001356)
   ,('2013-10-31',0.010754,-0.001578,NULL,0.003483,NULL,-0.004724,-0.001342)
   ,('2013-11-30',0.002402,0.020835,NULL,0.001,NULL,0.003954,-0.000306)
   ,('2013-12-31',0.004581,0.015689,NULL,0.002146,NULL,0.008333,0.001118)
   ,('2014-01-31',-0.00055,-0.001027,-0.008245,0.00732,NULL,0.004025,-0.007227)
   ,('2014-02-28',-0.001512,0.001653,-0.009029,0.009919,NULL,-0.008333,-0.003878)
   ,('2014-03-31',0.008784,0.004364,-0.011608,0.001,NULL,-0.008333,-0.004822)
   ,('2014-04-30',0.008412,-0.012369,-0.004692,0.004536,NULL,-0.006303,0.004306)
   ,('2014-05-31',0.003945,0.010651,-0.016833,0.001,NULL,-0.007974,0.005221)
   ,('2014-06-30',0.012371,0.01773,-0.010384,0.010593,NULL,-0.004781,-0.000731)
   ,('2014-07-31',0.011915,0.004308,-0.012965,0.001,NULL,0.007751,-0.009239)
   ,('2014-08-31',-0.013738,0.00039,0.000009,0.005139,0.001,-0.003319,-0.003636)
   ,('2014-09-30',-0.004081,0.01968,-0.008214,0.007976,0.001,-0.003799,0.005563)
   ,('2014-10-31',0.01608,0.015291,-0.002969,0.01303,0.001,-0.004645,0.001599)
   ,('2014-11-30',0.011241,0.012312,0.007088,0.00384,0.000852,0.006783,-0.008487)
   ,('2014-12-31',-0.004251,0.008737,-0.013576,0.001,0.001,-0.0034,0.001013)
   ,('2015-01-31',-0.004039,0.012938,-0.011891,0.004576,0.001,-0.004195,-0.002653)
   ,('2015-02-28',0.026326,0.019695,-0.013178,0.010737,0.001,0.006418,-0.00952)
   ,('2015-03-31',-0.000628,0.008029,0.005917,0.017461,0.00048,-0.00501,0.007879)
   ,('2015-04-30',0.005688,0.01249,-0.018813,0.001,-0.002104,0.003657,0.009886)
   ,('2015-05-31',0.010039,0.008442,-0.01465,0.001,0.001,0.001024,0.001695)
   ,('2015-06-30',-0.004267,0.001391,-0.022504,0.003104,0.001,-0.003507,0.009854)
   ,('2015-07-31',-0.001672,0.020558,-0.011859,0.001,0.001,NULL,0.008361)
   ,('2015-08-31',0.015726,0.017419,-0.004556,0.001,-0.000462,NULL,-0.007253)
   ,('2015-09-30',0.001977,0.007301,-0.00811,0.013011,-0.001032,NULL,0.009911)
   ,('2015-10-31',0.016201,0.00877,-0.005536,0.014527,-0.000833,NULL,0.009897)
   ,('2015-11-30',0.019996,-0.000785,-0.002161,0.001947,0.001,NULL,-0.007307)
   ,('2015-12-31',-0.003254,0.009595,-0.013785,0.001,0.001,NULL,0.007196)
   )n(dt,man1,man2,man3,man4,man5,man6,bmark)


To calculate the downside deviation for each manager using a minimum acceptable return of 0.5% we run the following SQL.
SELECT
   wct.DownsideDeviation(man1,0.005,'False') as man1
   ,wct.DownsideDeviation(man2,0.005,'False') as man2
   ,wct.DownsideDeviation(man3,0.005,'False') as man3
   ,wct.DownsideDeviation(man4,0.005,'False') as man4
   ,wct.DownsideDeviation(man5,0.005,'False') as man5
   ,wct.DownsideDeviation(man6,0.005,'False') as man6
   ,wct.DownsideDeviation(bmark,0.005,'False') as bmark
FROM
   #managers

This produces the following result.


Using the same data from the previous example in the #nmanagers table which is in 3rd normal form we perform the same calculation.
SELECT
   *
INTO
   #nmanagers
FROM (VALUES
    ('2012-12-31','man1',-0.002546)
   ,('2012-12-31','man4',0.003006)
   ,('2012-12-31','man6',0.005007)
   ,('2012-12-31','bmark',-0.001839)
   ,('2013-01-31','man1',0.009770)
   ,('2013-01-31','man4',0.001000)
   ,('2013-01-31','man6',-0.007579)
   ,('2013-01-31','bmark',0.008614)
   ,('2013-02-28','man1',0.024726)
   ,('2013-02-28','man4',0.005703)
   ,('2013-02-28','man6',0.006496)
   ,('2013-02-28','bmark',-0.004624)
   ,('2013-03-31','man1',0.000942)
   ,('2013-03-31','man4',0.007578)
   ,('2013-03-31','man6',0.008333)
   ,('2013-03-31','bmark',0.005031)
   ,('2013-04-30','man1',0.022139)
   ,('2013-04-30','man4',0.007118)
   ,('2013-04-30','man6',-0.007312)
   ,('2013-04-30','bmark',-0.005431)
   ,('2013-05-31','man1',0.019449)
   ,('2013-05-31','man4',0.005659)
   ,('2013-05-31','man6',-0.003902)
   ,('2013-05-31','bmark',-0.001878)
   ,('2013-06-30','man1',-0.007964)
   ,('2013-06-30','man4',0.003757)
   ,('2013-06-30','man6',-0.001899)
   ,('2013-06-30','bmark',-0.007060)
   ,('2013-07-31','man1',-0.008262)
   ,('2013-07-31','man2',-0.002824)
   ,('2013-07-31','man4',0.003762)
   ,('2013-07-31','man6',-0.007347)
   ,('2013-07-31','bmark',-0.001982)
   ,('2013-08-31','man1',0.009617)
   ,('2013-08-31','man2',0.007319)
   ,('2013-08-31','man4',0.002200)
   ,('2013-08-31','man6',-0.002116)
   ,('2013-08-31','bmark',0.003867)
   ,('2013-09-30','man1',-0.004118)
   ,('2013-09-30','man2',0.004128)
   ,('2013-09-30','man4',0.001394)
   ,('2013-09-30','man6',0.008333)
   ,('2013-09-30','bmark',0.001356)
   ,('2013-10-31','man1',0.010754)
   ,('2013-10-31','man2',-0.001578)
   ,('2013-10-31','man4',0.003483)
   ,('2013-10-31','man6',-0.004724)
   ,('2013-10-31','bmark',-0.001342)
   ,('2013-11-30','man1',0.002402)
   ,('2013-11-30','man2',0.020835)
   ,('2013-11-30','man4',0.001000)
   ,('2013-11-30','man6',0.003954)
   ,('2013-11-30','bmark',-0.000306)
   ,('2013-12-31','man1',0.004581)
   ,('2013-12-31','man2',0.015689)
   ,('2013-12-31','man4',0.002146)
   ,('2013-12-31','man6',0.008333)
   ,('2013-12-31','bmark',0.001118)
   ,('2014-01-31','man1',-0.000550)
   ,('2014-01-31','man2',-0.001027)
   ,('2014-01-31','man3',-0.008245)
   ,('2014-01-31','man4',0.007320)
   ,('2014-01-31','man6',0.004025)
   ,('2014-01-31','bmark',-0.007227)
   ,('2014-02-28','man1',-0.001512)
   ,('2014-02-28','man2',0.001653)
   ,('2014-02-28','man3',-0.009029)
   ,('2014-02-28','man4',0.009919)
   ,('2014-02-28','man6',-0.008333)
   ,('2014-02-28','bmark',-0.003878)
   ,('2014-03-31','man1',0.008784)
   ,('2014-03-31','man2',0.004364)
   ,('2014-03-31','man3',-0.011608)
   ,('2014-03-31','man4',0.001000)
   ,('2014-03-31','man6',-0.008333)
   ,('2014-03-31','bmark',-0.004822)
   ,('2014-04-30','man1',0.008412)
   ,('2014-04-30','man2',-0.012369)
   ,('2014-04-30','man3',-0.004692)
   ,('2014-04-30','man4',0.004536)
   ,('2014-04-30','man6',-0.006303)
   ,('2014-04-30','bmark',0.004306)
   ,('2014-05-31','man1',0.003945)
   ,('2014-05-31','man2',0.010651)
   ,('2014-05-31','man3',-0.016833)
   ,('2014-05-31','man4',0.001000)
   ,('2014-05-31','man6',-0.007974)
   ,('2014-05-31','bmark',0.005221)
   ,('2014-06-30','man1',0.012371)
   ,('2014-06-30','man2',0.017730)
   ,('2014-06-30','man3',-0.010384)
   ,('2014-06-30','man4',0.010593)
   ,('2014-06-30','man6',-0.004781)
   ,('2014-06-30','bmark',-0.000731)
   ,('2014-07-31','man1',0.011915)
   ,('2014-07-31','man2',0.004308)
   ,('2014-07-31','man3',-0.012965)
   ,('2014-07-31','man4',0.001000)
   ,('2014-07-31','man6',0.007751)
   ,('2014-07-31','bmark',-0.009239)
   ,('2014-08-31','man1',-0.013738)
   ,('2014-08-31','man2',0.000390)
   ,('2014-08-31','man3',0.000009)
   ,('2014-08-31','man4',0.005139)
   ,('2014-08-31','man5',0.001000)
   ,('2014-08-31','man6',-0.003319)
   ,('2014-08-31','bmark',-0.003636)
   ,('2014-09-30','man1',-0.004081)
   ,('2014-09-30','man2',0.019680)
   ,('2014-09-30','man3',-0.008214)
   ,('2014-09-30','man4',0.007976)
   ,('2014-09-30','man5',0.001000)
   ,('2014-09-30','man6',-0.003799)
   ,('2014-09-30','bmark',0.005563)
   ,('2014-10-31','man1',0.016080)
   ,('2014-10-31','man2',0.015291)
   ,('2014-10-31','man3',-0.002969)
   ,('2014-10-31','man4',0.013030)
   ,('2014-10-31','man5',0.001000)
   ,('2014-10-31','man6',-0.004645)
   ,('2014-10-31','bmark',0.001599)
   ,('2014-11-30','man1',0.011241)
   ,('2014-11-30','man2',0.012312)
   ,('2014-11-30','man3',0.007088)
   ,('2014-11-30','man4',0.003840)
   ,('2014-11-30','man5',0.000852)
   ,('2014-11-30','man6',0.006783)
   ,('2014-11-30','bmark',-0.008487)
   ,('2014-12-31','man1',-0.004251)
   ,('2014-12-31','man2',0.008737)
   ,('2014-12-31','man3',-0.013576)
   ,('2014-12-31','man4',0.001000)
   ,('2014-12-31','man5',0.001000)
   ,('2014-12-31','man6',-0.003400)
   ,('2014-12-31','bmark',0.001013)
   ,('2015-01-31','man1',-0.004039)
   ,('2015-01-31','man2',0.012938)
   ,('2015-01-31','man3',-0.011891)
   ,('2015-01-31','man4',0.004576)
   ,('2015-01-31','man5',0.001000)
   ,('2015-01-31','man6',-0.004195)
   ,('2015-01-31','bmark',-0.002653)
   ,('2015-02-28','man1',0.026326)
   ,('2015-02-28','man2',0.019695)
   ,('2015-02-28','man3',-0.013178)
   ,('2015-02-28','man4',0.010737)
   ,('2015-02-28','man5',0.001000)
   ,('2015-02-28','man6',0.006418)
   ,('2015-02-28','bmark',-0.009520)
   ,('2015-03-31','man1',-0.000628)
   ,('2015-03-31','man2',0.008029)
   ,('2015-03-31','man3',0.005917)
   ,('2015-03-31','man4',0.017461)
   ,('2015-03-31','man5',0.000480)
   ,('2015-03-31','man6',-0.005010)
   ,('2015-03-31','bmark',0.007879)
   ,('2015-04-30','man1',0.005688)
   ,('2015-04-30','man2',0.012490)
   ,('2015-04-30','man3',-0.018813)
   ,('2015-04-30','man4',0.001000)
   ,('2015-04-30','man5',-0.002104)
   ,('2015-04-30','man6',0.003657)
   ,('2015-04-30','bmark',0.009886)
   ,('2015-05-31','man1',0.010039)
   ,('2015-05-31','man2',0.008442)
   ,('2015-05-31','man3',-0.014650)
   ,('2015-05-31','man4',0.001000)
   ,('2015-05-31','man5',0.001000)
   ,('2015-05-31','man6',0.001024)
   ,('2015-05-31','bmark',0.001695)
   ,('2015-06-30','man1',-0.004267)
   ,('2015-06-30','man2',0.001391)
   ,('2015-06-30','man3',-0.022504)
   ,('2015-06-30','man4',0.003104)
   ,('2015-06-30','man5',0.001000)
   ,('2015-06-30','man6',-0.003507)
   ,('2015-06-30','bmark',0.009854)
   ,('2015-07-31','man1',-0.001672)
   ,('2015-07-31','man2',0.020558)
   ,('2015-07-31','man3',-0.011859)
   ,('2015-07-31','man4',0.001000)
   ,('2015-07-31','man5',0.001000)
   ,('2015-07-31','bmark',0.008361)
   ,('2015-08-31','man1',0.015726)
   ,('2015-08-31','man2',0.017419)
   ,('2015-08-31','man3',-0.004556)
   ,('2015-08-31','man4',0.001000)
   ,('2015-08-31','man5',-0.000462)
   ,('2015-08-31','bmark',-0.007253)
   ,('2015-09-30','man1',0.001977)
   ,('2015-09-30','man2',0.007301)
   ,('2015-09-30','man3',-0.008110)
   ,('2015-09-30','man4',0.013011)
   ,('2015-09-30','man5',-0.001032)
   ,('2015-09-30','bmark',0.009911)
   ,('2015-10-31','man1',0.016201)
   ,('2015-10-31','man2',0.008770)
   ,('2015-10-31','man3',-0.005536)
   ,('2015-10-31','man4',0.014527)
   ,('2015-10-31','man5',-0.000833)
   ,('2015-10-31','bmark',0.009897)
   ,('2015-11-30','man1',0.019996)
   ,('2015-11-30','man2',-0.000785)
   ,('2015-11-30','man3',-0.002161)
   ,('2015-11-30','man4',0.001947)
   ,('2015-11-30','man5',0.001000)
   ,('2015-11-30','bmark',-0.007307)
   ,('2015-12-31','man1',-0.003254)
   ,('2015-12-31','man2',0.009595)
   ,('2015-12-31','man3',-0.013785)
   ,('2015-12-31','man4',0.001000)
   ,('2015-12-31','man5',0.001000)
   ,('2015-12-31','bmark',0.007196)
)n(dt,man,R)
SELECT
    man as manager
   ,wct.DownsideDeviation(r,0.005,'False') as DownsideDeviation
FROM
   #nmanagers m
GROUP BY
   man

This produces the following result.

 

See Also

 



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