TITLE: Are these two notions of "dualizable" spectra equivalent?
QUESTION [11 upvotes]: A spectrum $X$ is dualizable if the natural map $$Map(X,\mathbb S) \wedge X \rightarrow Map(X,X)$$ is an equivalence of spectra. This is equivalent to having evaluation and coevaluation maps in the stable homotopy category
$$ X \wedge DX \rightarrow \mathbb S $$
$$ \mathbb S \rightarrow DX \wedge X $$
for which the usual composites
$$ X \rightarrow X \wedge DX \wedge X \rightarrow X $$
$$ DX \rightarrow DX \wedge X \wedge DX \rightarrow DX $$
give the identity in the homotopy category (cf. Lewis-May-Steinberger III.1.2). It is also well-known that this implies that $X \rightarrow D(DX)$ is an equivalence of spectra (LMS III.1.3(i)), but my question is

Is the converse true? Does $X \overset\sim\rightarrow D(DX)$ imply that $X$ is dualizable?

I understand that everything I have said holds in an arbitrary closed symmetric monoidal category, but I am willing to consider arguments that only work for spectra (or $R$-module spectra).

REPLY [7 votes]: Let $R$ be bounded below, bounded above and nontrivial, and work in $R$-modules.  Let $X = \bigvee_{n\in\mathbb{Z}} \Sigma^n R$.  Then $X \overset{\simeq}\to D(DX)$ is an equivalence, but $X$ is not dualizable. (Edit: Increased generality, based on a comment by Nardin.)