Goal

Examine how each asset contributes to portfolio standard deviation. This is to ensure that our risk is not concentrated in any one asset.

five stocks: “SPY”, “EFA”, “IJS”, “EEM”, “AGG” from 2012-12-31 to 2017-12-31

1 Import stock prices

2 Convert prices to returns

3 Component Contribution Step-by-Step

Refresh your memory on covariance with this video. Click this link Refresh your memory on matrix multiplication. Click this link

##                      AGG           EEM           EFA          IJS           SPY
## 2013-01-31 -0.0062314818 -0.0029356001  0.0366064100  0.052133090  4.992277e-02
## 2013-02-28  0.0058916378 -0.0231050073 -0.0129695690  0.016175342  1.267805e-02
## 2013-03-28  0.0009846231 -0.0102347632  0.0129695690  0.040258193  3.726795e-02
## 2013-04-30  0.0096398633  0.0120846592  0.0489676215  0.001222127  1.903029e-02
## 2013-05-31 -0.0202145584 -0.0494834017 -0.0306555928  0.041976501  2.333572e-02
## 2013-06-28 -0.0157782285 -0.0547285981 -0.0271445305 -0.001403001 -1.343443e-02
## 2013-07-31  0.0026876047  0.0131599274  0.0518603108  0.063541433  5.038593e-02
## 2013-08-30 -0.0082981768 -0.0257056421 -0.0197460608 -0.034743194 -3.045145e-02
## 2013-09-30  0.0111448200  0.0695889588  0.0753386824  0.063873520  3.115625e-02
## 2013-10-31  0.0082909175  0.0408612923  0.0320813207  0.034234077  4.526639e-02
## 2013-11-29 -0.0025098158 -0.0025943098  0.0054497637  0.041661326  2.920690e-02
## 2013-12-31 -0.0055827482 -0.0040743570  0.0215279276  0.012891799  2.559616e-02
## 2014-01-31  0.0152914929 -0.0903226763 -0.0534133570 -0.035775399 -3.588445e-02
## 2014-02-28  0.0037564572  0.0332206147  0.0595054100  0.045257762  4.451014e-02
## 2014-03-31 -0.0014804940  0.0380217630 -0.0046028114  0.013315309  8.261399e-03
## 2014-04-30  0.0081828727  0.0077727927  0.0165294223 -0.023184432  6.927258e-03
## 2014-05-30  0.0117211716  0.0290913076  0.0158285209  0.006205204  2.294117e-02
## 2014-06-30 -0.0005753667  0.0237337140  0.0091652618  0.037718656  2.043493e-02
## 2014-07-31 -0.0025121550  0.0135556888 -0.0263794989 -0.052009590 -1.352898e-02
## 2014-08-29  0.0114307148  0.0279046076  0.0018000838  0.043658115  3.870524e-02
## 2014-09-30 -0.0061669743 -0.0808566622 -0.0395983796 -0.061260315 -1.389236e-02
## 2014-10-31  0.0105840781  0.0140961089 -0.0026548517  0.068874721  2.327752e-02
## 2014-11-28  0.0065488021 -0.0155407440  0.0006252476  0.004773965  2.710141e-02
## 2014-12-31  0.0014752498 -0.0404423528 -0.0407468179  0.025295749 -2.539736e-03
## 2015-01-30  0.0203148056 -0.0068955117  0.0062266214 -0.054628196 -3.007728e-02
## 2015-02-27 -0.0089883941  0.0431359574  0.0614505880  0.056914381  5.468249e-02
## 2015-03-31  0.0037406253 -0.0150863608 -0.0143887132  0.010156846 -1.583076e-02
## 2015-04-30 -0.0032329599  0.0662815238  0.0358165791 -0.018417952  9.785875e-03
## 2015-05-29 -0.0043835346 -0.0419113842  0.0019527114  0.007510015  1.277425e-02
## 2015-06-30 -0.0108258784 -0.0297464117 -0.0316790005  0.004171511 -2.052124e-02
## 2015-07-31  0.0085848704 -0.0651780822  0.0201144184 -0.027375498  2.233776e-02
## 2015-08-31 -0.0033639692 -0.0925123972 -0.0771523474 -0.047268348 -6.288655e-02
## 2015-09-30  0.0080816230 -0.0318249587 -0.0451948496 -0.038464751 -2.584726e-02
## 2015-10-30  0.0006857283  0.0618081421  0.0640259951  0.063589600  8.163491e-02
## 2015-11-30 -0.0038982580 -0.0255601981 -0.0075560638  0.024415351  3.649114e-03
## 2015-12-31 -0.0019189923 -0.0389471341 -0.0235947978 -0.052157248 -1.743385e-02
## 2016-01-29  0.0123298344 -0.0516366963 -0.0567579689 -0.060306908 -5.106896e-02
## 2016-02-29  0.0088318577 -0.0082116920 -0.0339138341  0.020605475 -8.261510e-04
## 2016-03-31  0.0087086840  0.1218791055  0.0637455795  0.089910220  6.510043e-02
## 2016-04-29  0.0025460278  0.0040793093  0.0219750201  0.021044475  3.932909e-03
## 2016-05-31  0.0001351525 -0.0376286004 -0.0008559986  0.004396950  1.686877e-02
## 2016-06-30  0.0191672466  0.0445825600 -0.0244912633  0.008292171  3.469931e-03
## 2016-07-29  0.0054295935  0.0524420916  0.0390001498  0.049348431  3.582200e-02
## 2016-08-31 -0.0021561783  0.0087986612  0.0053269294  0.011260918  1.196811e-03
## 2016-09-30  0.0005157805  0.0248726013  0.0132790775  0.008614878  5.794373e-05
## 2016-10-31 -0.0082054546 -0.0083121396 -0.0224038355 -0.038134959 -1.748906e-02
## 2016-11-30 -0.0259897169 -0.0451620178 -0.0179744018  0.125246540  3.617600e-02
## 2016-12-30  0.0025380577 -0.0025298522  0.0267028177  0.031491678  2.006930e-02
## 2017-01-31  0.0021262175  0.0644314833  0.0323819966 -0.012143831  1.773617e-02
## 2017-02-28  0.0064381402  0.0172578364  0.0118364314  0.013428896  3.853926e-02
## 2017-03-31 -0.0005531281  0.0361890338  0.0318056710 -0.006532995  1.249270e-03
## 2017-04-28  0.0090297016  0.0168662927  0.0239521757  0.005107639  9.877229e-03
## 2017-05-31  0.0068472679  0.0280597909  0.0348102953 -0.022862482  1.401413e-02
## 2017-06-30 -0.0001829170  0.0092242165  0.0029559259  0.029151511  6.354867e-03
## 2017-07-31  0.0033339670  0.0565942026  0.0261878800  0.007481652  2.034573e-02
## 2017-08-31  0.0093699441  0.0232439210 -0.0004483592 -0.027564583  2.913498e-03
## 2017-09-29 -0.0057327004 -0.0004464642  0.0233429537  0.082321429  1.994907e-02
## 2017-10-31  0.0009780023  0.0322789003  0.0166533727  0.005915983  2.329081e-02
## 2017-11-30 -0.0014832734 -0.0038972165  0.0068703072  0.036913381  3.010802e-02
## 2017-12-29  0.0047396386  0.0369255154  0.0133982058 -0.003731191  1.205495e-02
##               AGG          EEM          EFA           IJS           SPY
## AGG  7.398467e-05 0.0001042108 4.178215e-05 -7.812103e-05 -9.031866e-06
## EEM  1.042108e-04 0.0017547120 1.039017e-03  6.437712e-04  6.795434e-04
## EFA  4.178215e-05 0.0010390167 1.064237e-03  6.490282e-04  6.975411e-04
## IJS -7.812103e-05 0.0006437712 6.490282e-04  1.565450e-03  8.290272e-04
## SPY -9.031866e-06 0.0006795434 6.975411e-04  8.290272e-04  7.408316e-04
##            [,1]
## [1,] 0.02347491
##               AGG         EEM         EFA         IJS         SPY
## [1,] 0.0003874127 0.009257147 0.005815631 0.005684461 0.002330253
## [1] 0.02347491
## # A tibble: 1 × 5
##     AGG   EEM   EFA   IJS   SPY
##   <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 0.017 0.394 0.248 0.242 0.099
## # A tibble: 5 × 2
##   asset contribution
##   <chr>        <dbl>
## 1 AGG          0.017
## 2 EEM          0.394
## 3 EFA          0.248
## 4 IJS          0.242
## 5 SPY          0.099

4 Component Contribution with a Custom Function

## # A tibble: 1 × 5
##     AGG   EEM   EFA   IJS   SPY
##   <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 0.017 0.394 0.248 0.242 0.099

5 Visualizing Component Contribution

6 Rolling Component Contribution

## # A tibble: 1 × 6
##   date         AGG   EEM   EFA   IJS   SPY
##   <date>     <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 2015-01-30 0.039 0.372 0.256 0.245 0.088
## # A tibble: 1 × 6
##   date         AGG   EEM   EFA   IJS   SPY
##   <date>     <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 2015-02-27 0.036 0.374 0.249 0.252 0.089
## # A tibble: 36 × 6
##    date         AGG   EEM   EFA   IJS   SPY
##    <date>     <dbl> <dbl> <dbl> <dbl> <dbl>
##  1 2015-01-30 0.039 0.372 0.256 0.245 0.088
##  2 2015-02-27 0.036 0.374 0.249 0.252 0.089
##  3 2015-03-31 0.027 0.37  0.255 0.255 0.092
##  4 2015-04-30 0.027 0.372 0.256 0.252 0.093
##  5 2015-05-29 0.024 0.385 0.254 0.246 0.092
##  6 2015-06-30 0.018 0.383 0.248 0.257 0.094
##  7 2015-07-31 0.014 0.375 0.253 0.261 0.097
##  8 2015-08-31 0.013 0.404 0.237 0.257 0.09 
##  9 2015-09-30 0.012 0.407 0.248 0.238 0.094
## 10 2015-10-30 0.003 0.405 0.244 0.243 0.105
## # ℹ 26 more rows