I am still 30+ years away from retirement, so I have a relatively long time to grow my retirement funds. In the first 10+ years of my career, I haven't sunk a huge portion of my income into my employer IRA (only 3% of my salary; employer matches that), but what I have invested has done well (as everyone in the market has) over the past several years. However, as the Dow is entering uncharted territory nearly every day, I am now wondering if it would make sense to sell some of my current assets and put that money in either lower-risk investments (bonds) or perhaps some sectors that are currently depressed but seem to have recovery potential. I would probably continue to invest my future contributions in my current allocations to start building value again in higher-yield-potential investments, but I feel like this would at least protect my current account value from a market crash.

Am I way off base, or is this a sound strategy? Also, are there any tax implications from selling assets held in my IRA, as long as I don't withdraw the funds from the account?

TIA