in reply to Issue with looping through XML::LibXML::Reader

The problem seems to be that you are reading the next Instrmt element in a while loop and as a result you skip the parent MktDataFull elements.

If you change the while() to an if() it should fix the main issue.

... if ( $reader->nextElement( 'Instrmt' ) ) { my $Sym = $reader->getAttribute( 'Sym' ); ...