my @problems;
foreach my $row ( @$data ) {
    my %categories;
    @categories{ cusip isin sedol ticker } = @$row;
    foreach my $category ( keys %categories ) {
        next if $category eq 'ticker';
        if( not defined( $categories{$category} ) {
            push @problems, 
                 problem( $category, $categories{ticker} ); 
            next;
        }

    }
}

sub problem {
    my ( $problem_tag, $ticker ) = @_;
    my $issue = "Missing $problem_tag for $ticker";
    print $issue, "\n";    
    return $issue;
}