!"#$"%&#
!"
!#$ %&$ '() * +,$
-$ + ./0/12&13
#
#
•
'()*+*,-.!/!01
•
2,034*+*,+56*07
•
'()*+*,-.!/!01
•
2,034*+*,+56*07
%
%
•
2898:
•
2,034*+*,8:
•
2898:
•
2,034*+*,8:
;
;
•
<=>8:
•
?@A5 ?
•
<=>8:
•
?@A5 ?
4
5
&6
%&B B
789
#&B %&B
:;<
;&B #%B
<
&B $B
CDDEF
**34%0,956 -<,G1+%0,9563HIJG,9+)K>G31L-MN-/M
*,O!
P#!QR-GS35"@/(>GTGS38/-,R0,956DU@/
GS3-,56-,P
6VW/L
K,9-
K@XX"O/'+
.!/!01
YL!/W/LK>
(-K@3
,G1
.!/!01+#56
'LK,ZM,[0\++!]^*,R4KA
5@I
*,G *<*,!_K`
L+56*,K`
&
L+56*,K`&
5
03031)[ZG31*,aK`&JK`
&
&
P
CPP
r
tt
+
=
•
NGR9LM8:KL0,956b.!/!01,G1
•
c+*,+RIK,LdG31G,O]eK,Lf^.!/!01
*,*341M_/-*341MW//+\56
•
6,L8
*
g
W
•
6,L-0J"*+*,-,
(;=>?>@
G.!/!010-RG9031hMNM_i
3H!+<j,*34G31Gk
2R0i0-3JG,GRMNLK,LOGR8,GR)<]4GdJ<
,G1
lk2dG,034-!,!LGR*+*,+L'M>
mn
%
σσ
=
( )
∑
−==
jj
prrVar
%
%
σ
( )
∑
−==
%
%
#
rr
N
Var
j
σ
&6
%&B B
789AB
#&B %&B
CD
;&B #%B
<
&B $B
&6
%&B B
789AB
#&B %&B
CD
;&B #%B
<
&B $B
E>"
AB
TSSL mong đợi
5F;=>
&6
&"%&
17,5%
&"#&%
789AB
&"#& &"&&%
5FD
&";& &"&#%
5GH
&"& &"#&%
IJ0KL
&6
&"&
5,5%
&"&&&&%
789AB
&"%& &"&%#&%
5FD
&"#% &"&;&%
5GH
&&$ &"&&#%%
IJI0M
E>"
AB
TSSL mong đợi
5F;=>
&6
&"%&
17,5%
789AB
&"#& &"&&%
5FD
&";& &"&#%
5GH
&"& &"#&%
&6
&"&
5,5%
789AB
&"%& &"&%#&%
5FD
&"#% &"&;&%
5GH
&&$ &"&&#%%
íà;=>>@
2d!,!LGR*+*,+%IK,L"o8bD!_M3H!
5pg
5p0-3JG,*+*,*\GH<,G1D!_M3H!-0J"*+*,-0J
N
OP5QR
OP4QR
E>"
AB
TSSL mong đợi
5F;=>
&6
&"%&
17,5%
&"#&%
789AB
&"#& &"&&%
5FD
&";& &"&#%
5GH
&"& &"#&%
IJ0KL
&6
&"&
5,5%
&"&&&&%
789AB
&"%& &"&%#&%
5FD
&"#% &"&;&%
5GH
&&$ &"&&#%%
IJI0M
E>"
AB
TSSL mong đợi
5F;=>
&6
&"%&
17,5%
789AB
&"#& &"&&%
5FD
&";& &"&#%
5GH
&"& &"#&%
&6
&"&
5,5%
789AB
&"%& &"&%#&%
5FD
&"#% &"&;&%
5GH
&&$ &"&&#%%
,!L-6>0Z
Kết luận : CK A có Hệ số phương sai CV nhỏ hơn Hệ số phương sai CV của CK B.
Do đó, CK A có rủi ro thấp hơn CK B.
Ông C nên chọn CK A để giảm thiểu rủi ro.
OP5QR
OP4QR
#YLG
%AM3HGR0n
%
(SNT9> (SNE>U
;</nm
%
%
%
g
%
g
</G31GR </G31GR
0i 0i
g g
q.!/!01IJA*9
q<K`r
M
qWL!/W*A_
q!_(!L
9>
V
&6 %&B B
789 #&B %&B
:;< ;&B #%B
< &B $B
P%!Q@5!__0-#&&s-@_GS3-,%56 -5MN
K@GS3&B-,IK,L "&B-,IK,LDUG898:
3Z0-*+*,!,JGS356*07P
II&#&%
&;
&
&&&t&u
&$
#&
###%#;
#
#
#
#t#u
#$
%&
**34%0,956 -<,G1+%0,9563HIJG,9+)K>G31L-MN-/M
*,O!
T!/!01,G1+8:
DMM3H!
D!_3H(
3H!+8:IK,L
+ WXYZ$YW4 ,[
.!/!01,G1+8:v0>\A94J5<-OA(N()<,G1+a
IK,L*0w
*
M
gW
xW
*
.!/!01,G1+8:
W
"
W
.*r_GS3+56 "56
"
<,G1+56 "56
]7^_7$ `a$,Wb!a$Z44 ,[
•
Hc9.!/!01,G1+8:vIK,L,[-!
•
C\>
*,G
]7^_7$ `a$,Wb!a$Z44 ,[
∑
=
j
jp
rxr
j,G)
W
g&B"
W
g&B"
<8:n*
m
5@I*
gW
xW
*
g&n#t"Bmx&nBmg#%tB
B"=
B
r
B"#t=
A
r
A
r
B
r
$d(( efb74$
•
2,034!O>GR<+IK,L!,JL*K`r+o*,_3H(J
•
5@I
*,G
*
"
*
<+IK,L "]A_
"
<,G1+IK,L "
( )( )
∑
=
−−=
n
i
B
iB
A
iAi
rrrrpBACOV
#
m"n
( )( )
∑
=
−−=
n
i
B
iB
A
iA
rrrr
N
BACOV
#
#
m"n
"
A
r
B
r
$d(( efb74$
p8:
W
g&B"
W
g&B"
MM3H!+<^'MSn m-nm
g&&&ut
V
&6
%&B B
789
#&B %&B
:;<
;&B #%B
<
&B $B
( )( )
∑
=
−−=
n
i
B
iB
A
iA
rrrr
N
BACOV
#
#
m"n
B"=
B
r
B"#t=
A
r
5@I
d7gefbh^4
*,G
!_3H(<^IK,L -IK,L
MM3H+8:
GR0i+IK,L "
IK,L
( )
y
zz
{
BA
AB
BA,COV
=
AB
{
( )
BA,COV
BA
zz
|#y#}{ −∈
AB
•
D!_3H(g#
Tyû suaát sinh lôïi A
Tyû suaát sinh lôïi B
•
>%IK,L<8db3JAo3H(WLG
•
D!_3H(g#
Tyû suaát sinh lôïi A
Tyû suaát sinh lôïi B
•
>%IK,L<8d313JAo3H(M+G
•
D!_3H(g&
Tyû suaát sinh lôïi A
Tyû suaát sinh lôïi B
$d(( efb74$
p8:
W
g&B"
W
g&B"
!_3H(+%56n m-nm
E>"
AB
TSSL mong đợi
!=>>@
g
&6
&"%&
17,5%
789AB
&"#&
5FD
&";&
5GH
&"&
&6
&"&
5,5%
789AB
&"%&
5FD
&"#%
5GH
&&$
E>"
AB
TSSL mong đợi
!=>>@
&6
&"%&
17,5%
789AB
&"#&
5FD
&";&
5GH
&"&
&6
&"&
5,5%
789AB
&"%&
5FD
&"#%
5GH
&&$
R/I)II3L
B"=
B
r
B"#t=
A
r
( )
BA
AB
BA,COV
zz
{ =
#;$&
##BW%uB
{
−=
=
0.004875-
AB
( )( )
∑
=
−−=
n
i
B
iB
A
iA
rrrr
N
BACOV
#
#
m"n