A trace module comprising: monitoring circuitry to monitor processing of instructions by processing circuitry ; and trace output circuitry to output a sequence of elements indicative of outcomes of the processing of the instructions by the processing circuitry; in which: the trace output circuitry is capable of outputting: a commit element indicative of the processing circuitry having committed one or more speculatively executed instructions represented by at least one oldest speculative element in a commit window of the sequence of elements, the commit window comprising a portion of the sequence of elements comprising at least one speculative element representing at least one speculatively executed instruction which is still to be committed by the processing circuitry, where the commit element is also indicative that following the commit element said at least one oldest speculative element is to be excluded from the commit window; and a commit window move element (CWM) indicative that, while one or more speculatively executed instructions represented by an oldest remaining speculative element of the sequence of elements remain uncommitted by the processing circuitry, the commit window should move relative to the oldest remaining speculative element to change which speculative element is the oldest speculative element of the commit window. monitoring circuitry to monitor processing of instructions by processing circuitry ; and trace output circuitry to output a sequence of elements indicative of outcomes of the processing of the instructions by the processing circuitry; in which: the trace output circuitry is capable of outputting: a commit element indicative of the processing circuitry having committed one or more speculatively executed instructions represented by at least one oldest speculative element in a commit window of the sequence of elements, the commit window comprising a portion of the sequence of elements comprising at least one speculative element representing at least one speculatively executed instruction which is still to be committed by the processing circuitry, where the commit element is also indicative that following the commit element said at least one oldest speculative element is to be excluded from the commit window; and a commit window move element (CWM) indicative that, while one or more speculatively executed instructions represented by an oldest remaining speculative element of the sequence of elements remain uncommitted by the processing circuitry, the commit window should move relative to the oldest remaining speculative element to change which speculative element is the oldest speculative element of the commit window. the trace output circuitry is capable of outputting: a commit element indicative of the processing circuitry having committed one or more speculatively executed instructions represented by at least one oldest speculative element in a commit window of the sequence of elements, the commit window comprising a portion of the sequence of elements comprising at least one speculative element representing at least one speculatively executed instruction which is still to be committed by the processing circuitry, where the commit element is also indicative that following the commit element said at least one oldest speculative element is to be excluded from the commit window; and a commit window move element (CWM) indicative that, while one or more speculatively executed instructions represented by an oldest remaining speculative element of the sequence of elements remain uncommitted by the processing circuitry, the commit window should move relative to the oldest remaining speculative element to change which speculative element is the oldest speculative element of the commit window. <EOS>