#!usr/bin/perl
use strict;
use warnings;

my @lines;

while (<DATA>)
{
   push @lines,$_;
}

@lines = sort by_col2 @lines;
print @lines;

sub by_col2
{
    my ($A_col2) = (split ' ', $a)[1];
    my ($B_col2) = (split ' ', $b)[1];
         $A_col2 cmp $B_col2;
}

=prints
912796HD4       Bill    4-Week  2016-01-26      2016-01-28      2016-02-25      99.977056       NULL
912796HD4       Bill    4-Week  2016-01-26      2016-01-28      2016-02-25      99.977056       NULL
912810RS9       Bond    30-Year 2016-05-12      2016-05-16      2046-05-15      97.619462       2.500000
912810RQ3       Bond    29-Year 2016-04-14      2016-04-15      2046-02-15      98.011430       2.500000
912828Q86       Note    1-Year  2016-05-25      2016-05-27      2018-04-30      100.003850      NULL
912828N71       Note    9-Year  2016-05-19      2016-05-31      2026-01-15      103.533587      0.625000
=cut


__DATA__
912828Q86       Note    1-Year  2016-05-25      2016-05-27      2018-04-30      100.003850      NULL
912796HD4       Bill    4-Week  2016-01-26      2016-01-28      2016-02-25      99.977056       NULL
912810RS9       Bond    30-Year 2016-05-12      2016-05-16      2046-05-15      97.619462       2.500000
912810RQ3       Bond    29-Year 2016-04-14      2016-04-15      2046-02-15      98.011430       2.500000
912796HD4       Bill    4-Week  2016-01-26      2016-01-28      2016-02-25      99.977056       NULL
912828N71       Note    9-Year  2016-05-19      2016-05-31      2026-01-15      103.533587      0.625000